Oligomeric Rings of the Sec61p Complex Induced by Ligands Required for Protein Translocation
Identifieur interne : 002689 ( Istex/Corpus ); précédent : 002688; suivant : 002690Oligomeric Rings of the Sec61p Complex Induced by Ligands Required for Protein Translocation
Auteurs : Dorit Hanein ; Kent E. S Matlack ; Berit Jungnickel ; Kathrin Plath ; Kai-Uwe Kalies ; Kenneth R. Miller ; Tom A. Rapoport ; Christopher W. AkeySource :
- Cell [ 0092-8674 ] ; 1996.
English descriptors
- Teeft :
- Average diameter, Bilayer, Biol, Blobel, Canine, Cell biol, Central pore, Corresponding averages, Cotranslational, Cotranslational pathway, Cotranslational translocation, Cytoplasmic surface, Data sets, Electron microscopy, Endoplasmic, Endoplasmic reticulum, Endoplasmic reticulum membrane, Experimental procedures, Fracture, Freeze fracture, Gating, Gorlich, Hartmann, Heptameric, Heterotrimers, Image processing, Individual particles, Inset, Intramembranous particles, Jungnickel, Kalies, Koac, Large numbers, Lipid, Lipid bilayer, Magnesium acetate, Membrane, Membrane proteins, Microscopy, Microsome, Morphology, Nascent, Nascent chain, Native membranes, Negative stain, Oligomer, Oligomeric, Oligomeric rings, Oligomerization, Oligomers, Panzner, Pathway, Phospholipid bilayer, Pmol, Polypeptide, Pore, Posttranslational, Posttranslational pathway, Posttranslational protein transport, Posttranslational translocation, Posttranslational transport, Protein translocation, Protein transport, Proteoliposomes, Proteoliposomes reconstituted, Quasipentagonal, Quasipentagonal appearance, Quasipentagonal morphology, Rapoport, Reconstituted, Reconstituted membranes, Reconstituted proteoliposomes, Reconstitution, Reticulum, Ribosome, Ring structures, Rings, Rotary shadowing, Rough endoplasmic reticulum, Same buffer, Signal sequence, Subunit, Translocating, Translocation, Unstained specimens, Yeast, Yeast ribosomes.
Abstract
Abstract: The heterotrimeric Sec61p complex is a major component of the protein-conducting channel of the endoplasmic reticulum (ER) membrane, associating with either ribosomes or the Sec62/63 complex to perform co- and posttranslational transport, respectively. We show by electron microscopy that purified mammalian and yeast Sec61p complexes in detergent form cylindrical oligomers with a diameter of ∼85 Å and a central pore of ∼20 Å. Each oligomer contains 3–4 heterotrimers. Similar ring structures are seen in reconstituted proteoliposomes and native membranes. Oligomer formation by the reconstituted Sec61p complex is stimulated by its association with ribosomes or the Sec62/63p complex. We propose that these cylindrical oligomers represent protein-conducting channels of the ER, formed by ligands specific for co- and posttranslational transport.
Url:
DOI: 10.1016/S0092-8674(00)81391-4
Links to Exploration step
ISTEX:27D677446EBDA74678F1FCB925F938D7A7639226Le document en format XML
<record><TEI wicri:istexFullTextTei="biblStruct"><teiHeader><fileDesc><titleStmt><title xml:lang="en">Oligomeric Rings of the Sec61p Complex Induced by Ligands Required for Protein Translocation</title><author><name sortKey="Hanein, Dorit" sort="Hanein, Dorit" uniqKey="Hanein D" first="Dorit" last="Hanein">Dorit Hanein</name><affiliation><mods:affiliation>Department of Biophysics, Boston University School of Medicine, Boston, Massashusetts 02218-2394, USA</mods:affiliation></affiliation></author><author><name sortKey="Matlack, Kent E S" sort="Matlack, Kent E S" uniqKey="Matlack K" first="Kent E. S" last="Matlack">Kent E. S Matlack</name><affiliation><mods:affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</mods:affiliation></affiliation></author><author><name sortKey="Jungnickel, Berit" sort="Jungnickel, Berit" uniqKey="Jungnickel B" first="Berit" last="Jungnickel">Berit Jungnickel</name><affiliation><mods:affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</mods:affiliation></affiliation></author><author><name sortKey="Plath, Kathrin" sort="Plath, Kathrin" uniqKey="Plath K" first="Kathrin" last="Plath">Kathrin Plath</name><affiliation><mods:affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</mods:affiliation></affiliation><affiliation><mods:affiliation>Max Delbrueck Center for Molecular Medicine, Robert Roessle Str. 10, 13122 Berlin-Buch, Germany</mods:affiliation></affiliation></author><author><name sortKey="Kalies, Kai Uwe" sort="Kalies, Kai Uwe" uniqKey="Kalies K" first="Kai-Uwe" last="Kalies">Kai-Uwe Kalies</name><affiliation><mods:affiliation>Max Delbrueck Center for Molecular Medicine, Robert Roessle Str. 10, 13122 Berlin-Buch, Germany</mods:affiliation></affiliation></author><author><name sortKey="Miller, Kenneth R" sort="Miller, Kenneth R" uniqKey="Miller K" first="Kenneth R" last="Miller">Kenneth R. Miller</name><affiliation><mods:affiliation>Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912, USA</mods:affiliation></affiliation></author><author><name sortKey="Rapoport, Tom A" sort="Rapoport, Tom A" uniqKey="Rapoport T" first="Tom A" last="Rapoport">Tom A. Rapoport</name><affiliation><mods:affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</mods:affiliation></affiliation></author><author><name sortKey="Akey, Christopher W" sort="Akey, Christopher W" uniqKey="Akey C" first="Christopher W" last="Akey">Christopher W. Akey</name><affiliation><mods:affiliation>Department of Biophysics, Boston University School of Medicine, Boston, Massashusetts 02218-2394, USA</mods:affiliation></affiliation><affiliation><mods:affiliation>Correspondence: Christopher W. Akey, 617 638 4051 (phone), 617 638 4041 (fax)</mods:affiliation></affiliation><affiliation><mods:affiliation>E-mail: akey@med-biophm.bu.edu</mods:affiliation></affiliation></author></titleStmt><publicationStmt><idno type="wicri:source">ISTEX</idno><idno type="RBID">ISTEX:27D677446EBDA74678F1FCB925F938D7A7639226</idno><date when="1996" year="1996">1996</date><idno type="doi">10.1016/S0092-8674(00)81391-4</idno><idno type="url">https://api.istex.fr/ark:/67375/6H6-2LWHHVL0-5/fulltext.pdf</idno><idno type="wicri:Area/Istex/Corpus">002689</idno><idno type="wicri:explorRef" wicri:stream="Istex" wicri:step="Corpus" wicri:corpus="ISTEX">002689</idno></publicationStmt><sourceDesc><biblStruct><analytic><title level="a" type="main" xml:lang="en">Oligomeric Rings of the Sec61p Complex Induced by Ligands Required for Protein Translocation</title><author><name sortKey="Hanein, Dorit" sort="Hanein, Dorit" uniqKey="Hanein D" first="Dorit" last="Hanein">Dorit Hanein</name><affiliation><mods:affiliation>Department of Biophysics, Boston University School of Medicine, Boston, Massashusetts 02218-2394, USA</mods:affiliation></affiliation></author><author><name sortKey="Matlack, Kent E S" sort="Matlack, Kent E S" uniqKey="Matlack K" first="Kent E. S" last="Matlack">Kent E. S Matlack</name><affiliation><mods:affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</mods:affiliation></affiliation></author><author><name sortKey="Jungnickel, Berit" sort="Jungnickel, Berit" uniqKey="Jungnickel B" first="Berit" last="Jungnickel">Berit Jungnickel</name><affiliation><mods:affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</mods:affiliation></affiliation></author><author><name sortKey="Plath, Kathrin" sort="Plath, Kathrin" uniqKey="Plath K" first="Kathrin" last="Plath">Kathrin Plath</name><affiliation><mods:affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</mods:affiliation></affiliation><affiliation><mods:affiliation>Max Delbrueck Center for Molecular Medicine, Robert Roessle Str. 10, 13122 Berlin-Buch, Germany</mods:affiliation></affiliation></author><author><name sortKey="Kalies, Kai Uwe" sort="Kalies, Kai Uwe" uniqKey="Kalies K" first="Kai-Uwe" last="Kalies">Kai-Uwe Kalies</name><affiliation><mods:affiliation>Max Delbrueck Center for Molecular Medicine, Robert Roessle Str. 10, 13122 Berlin-Buch, Germany</mods:affiliation></affiliation></author><author><name sortKey="Miller, Kenneth R" sort="Miller, Kenneth R" uniqKey="Miller K" first="Kenneth R" last="Miller">Kenneth R. Miller</name><affiliation><mods:affiliation>Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912, USA</mods:affiliation></affiliation></author><author><name sortKey="Rapoport, Tom A" sort="Rapoport, Tom A" uniqKey="Rapoport T" first="Tom A" last="Rapoport">Tom A. Rapoport</name><affiliation><mods:affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</mods:affiliation></affiliation></author><author><name sortKey="Akey, Christopher W" sort="Akey, Christopher W" uniqKey="Akey C" first="Christopher W" last="Akey">Christopher W. Akey</name><affiliation><mods:affiliation>Department of Biophysics, Boston University School of Medicine, Boston, Massashusetts 02218-2394, USA</mods:affiliation></affiliation><affiliation><mods:affiliation>Correspondence: Christopher W. Akey, 617 638 4051 (phone), 617 638 4041 (fax)</mods:affiliation></affiliation><affiliation><mods:affiliation>E-mail: akey@med-biophm.bu.edu</mods:affiliation></affiliation></author></analytic><monogr></monogr><series><title level="j">Cell</title><title level="j" type="abbrev">CELL</title><idno type="ISSN">0092-8674</idno><imprint><publisher>ELSEVIER</publisher><date type="published" when="1996">1996</date><biblScope unit="volume">87</biblScope><biblScope unit="issue">4</biblScope><biblScope unit="page" from="721">721</biblScope><biblScope unit="page" to="732">732</biblScope></imprint><idno type="ISSN">0092-8674</idno></series></biblStruct></sourceDesc><seriesStmt><idno type="ISSN">0092-8674</idno></seriesStmt></fileDesc><profileDesc><textClass><keywords scheme="Teeft" xml:lang="en"><term>Average diameter</term><term>Bilayer</term><term>Biol</term><term>Blobel</term><term>Canine</term><term>Cell biol</term><term>Central pore</term><term>Corresponding averages</term><term>Cotranslational</term><term>Cotranslational pathway</term><term>Cotranslational translocation</term><term>Cytoplasmic surface</term><term>Data sets</term><term>Electron microscopy</term><term>Endoplasmic</term><term>Endoplasmic reticulum</term><term>Endoplasmic reticulum membrane</term><term>Experimental procedures</term><term>Fracture</term><term>Freeze fracture</term><term>Gating</term><term>Gorlich</term><term>Hartmann</term><term>Heptameric</term><term>Heterotrimers</term><term>Image processing</term><term>Individual particles</term><term>Inset</term><term>Intramembranous particles</term><term>Jungnickel</term><term>Kalies</term><term>Koac</term><term>Large numbers</term><term>Lipid</term><term>Lipid bilayer</term><term>Magnesium acetate</term><term>Membrane</term><term>Membrane proteins</term><term>Microscopy</term><term>Microsome</term><term>Morphology</term><term>Nascent</term><term>Nascent chain</term><term>Native membranes</term><term>Negative stain</term><term>Oligomer</term><term>Oligomeric</term><term>Oligomeric rings</term><term>Oligomerization</term><term>Oligomers</term><term>Panzner</term><term>Pathway</term><term>Phospholipid bilayer</term><term>Pmol</term><term>Polypeptide</term><term>Pore</term><term>Posttranslational</term><term>Posttranslational pathway</term><term>Posttranslational protein transport</term><term>Posttranslational translocation</term><term>Posttranslational transport</term><term>Protein translocation</term><term>Protein transport</term><term>Proteoliposomes</term><term>Proteoliposomes reconstituted</term><term>Quasipentagonal</term><term>Quasipentagonal appearance</term><term>Quasipentagonal morphology</term><term>Rapoport</term><term>Reconstituted</term><term>Reconstituted membranes</term><term>Reconstituted proteoliposomes</term><term>Reconstitution</term><term>Reticulum</term><term>Ribosome</term><term>Ring structures</term><term>Rings</term><term>Rotary shadowing</term><term>Rough endoplasmic reticulum</term><term>Same buffer</term><term>Signal sequence</term><term>Subunit</term><term>Translocating</term><term>Translocation</term><term>Unstained specimens</term><term>Yeast</term><term>Yeast ribosomes</term></keywords></textClass><langUsage><language ident="en">en</language></langUsage></profileDesc></teiHeader><front><div type="abstract" xml:lang="en">Abstract: The heterotrimeric Sec61p complex is a major component of the protein-conducting channel of the endoplasmic reticulum (ER) membrane, associating with either ribosomes or the Sec62/63 complex to perform co- and posttranslational transport, respectively. We show by electron microscopy that purified mammalian and yeast Sec61p complexes in detergent form cylindrical oligomers with a diameter of ∼85 Å and a central pore of ∼20 Å. Each oligomer contains 3–4 heterotrimers. Similar ring structures are seen in reconstituted proteoliposomes and native membranes. Oligomer formation by the reconstituted Sec61p complex is stimulated by its association with ribosomes or the Sec62/63p complex. We propose that these cylindrical oligomers represent protein-conducting channels of the ER, formed by ligands specific for co- and posttranslational transport.</div></front></TEI><istex><corpusName>elsevier</corpusName><keywords><teeft><json:string>ribosome</json:string><json:string>translocation</json:string><json:string>reconstituted</json:string><json:string>proteoliposomes</json:string><json:string>oligomers</json:string><json:string>electron microscopy</json:string><json:string>posttranslational</json:string><json:string>central pore</json:string><json:string>subunit</json:string><json:string>reticulum</json:string><json:string>endoplasmic</json:string><json:string>microsome</json:string><json:string>heptameric</json:string><json:string>pathway</json:string><json:string>biol</json:string><json:string>rapoport</json:string><json:string>panzner</json:string><json:string>cotranslational</json:string><json:string>oligomeric</json:string><json:string>blobel</json:string><json:string>gorlich</json:string><json:string>lipid</json:string><json:string>quasipentagonal</json:string><json:string>cell biol</json:string><json:string>reconstitution</json:string><json:string>jungnickel</json:string><json:string>polypeptide</json:string><json:string>bilayer</json:string><json:string>oligomerization</json:string><json:string>hartmann</json:string><json:string>nascent chain</json:string><json:string>yeast</json:string><json:string>pmol</json:string><json:string>reconstituted proteoliposomes</json:string><json:string>oligomer</json:string><json:string>koac</json:string><json:string>heterotrimers</json:string><json:string>membrane</json:string><json:string>nascent</json:string><json:string>pore</json:string><json:string>gating</json:string><json:string>proteoliposomes reconstituted</json:string><json:string>kalies</json:string><json:string>translocating</json:string><json:string>ring structures</json:string><json:string>endoplasmic reticulum</json:string><json:string>magnesium acetate</json:string><json:string>negative stain</json:string><json:string>endoplasmic reticulum membrane</json:string><json:string>native membranes</json:string><json:string>canine</json:string><json:string>fracture</json:string><json:string>cotranslational pathway</json:string><json:string>inset</json:string><json:string>protein transport</json:string><json:string>signal sequence</json:string><json:string>freeze fracture</json:string><json:string>same buffer</json:string><json:string>cotranslational translocation</json:string><json:string>individual particles</json:string><json:string>posttranslational pathway</json:string><json:string>phospholipid bilayer</json:string><json:string>average diameter</json:string><json:string>reconstituted membranes</json:string><json:string>yeast ribosomes</json:string><json:string>morphology</json:string><json:string>microscopy</json:string><json:string>rotary shadowing</json:string><json:string>data sets</json:string><json:string>corresponding averages</json:string><json:string>quasipentagonal appearance</json:string><json:string>large numbers</json:string><json:string>experimental procedures</json:string><json:string>oligomeric rings</json:string><json:string>intramembranous particles</json:string><json:string>cytoplasmic surface</json:string><json:string>unstained specimens</json:string><json:string>posttranslational translocation</json:string><json:string>protein translocation</json:string><json:string>posttranslational protein transport</json:string><json:string>quasipentagonal morphology</json:string><json:string>lipid bilayer</json:string><json:string>image processing</json:string><json:string>membrane proteins</json:string><json:string>posttranslational transport</json:string><json:string>rough endoplasmic reticulum</json:string><json:string>rings</json:string></teeft></keywords><author><json:item><name>Dorit Hanein</name><affiliations><json:string>Department of Biophysics, Boston University School of Medicine, Boston, Massashusetts 02218-2394, USA</json:string></affiliations></json:item><json:item><name>Kent E.S Matlack</name><affiliations><json:string>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</json:string></affiliations></json:item><json:item><name>Berit Jungnickel</name><affiliations><json:string>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</json:string></affiliations></json:item><json:item><name>Kathrin Plath</name><affiliations><json:string>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</json:string><json:string>Max Delbrueck Center for Molecular Medicine, Robert Roessle Str. 10, 13122 Berlin-Buch, Germany</json:string></affiliations></json:item><json:item><name>Kai-Uwe Kalies</name><affiliations><json:string>Max Delbrueck Center for Molecular Medicine, Robert Roessle Str. 10, 13122 Berlin-Buch, Germany</json:string></affiliations></json:item><json:item><name>Kenneth R Miller</name><affiliations><json:string>Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912, USA</json:string></affiliations></json:item><json:item><name>Tom A Rapoport</name><affiliations><json:string>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</json:string></affiliations></json:item><json:item><name>Christopher W Akey</name><affiliations><json:string>Department of Biophysics, Boston University School of Medicine, Boston, Massashusetts 02218-2394, USA</json:string><json:string>Correspondence: Christopher W. Akey, 617 638 4051 (phone), 617 638 4041 (fax)</json:string><json:string>E-mail: akey@med-biophm.bu.edu</json:string></affiliations></json:item></author><arkIstex>ark:/67375/6H6-2LWHHVL0-5</arkIstex><language><json:string>eng</json:string></language><originalGenre><json:string>Full-length article</json:string></originalGenre><abstract>Abstract: The heterotrimeric Sec61p complex is a major component of the protein-conducting channel of the endoplasmic reticulum (ER) membrane, associating with either ribosomes or the Sec62/63 complex to perform co- and posttranslational transport, respectively. We show by electron microscopy that purified mammalian and yeast Sec61p complexes in detergent form cylindrical oligomers with a diameter of ∼85 Å and a central pore of ∼20 Å. Each oligomer contains 3–4 heterotrimers. Similar ring structures are seen in reconstituted proteoliposomes and native membranes. Oligomer formation by the reconstituted Sec61p complex is stimulated by its association with ribosomes or the Sec62/63p complex. We propose that these cylindrical oligomers represent protein-conducting channels of the ER, formed by ligands specific for co- and posttranslational transport.</abstract><qualityIndicators><score>8.428</score><pdfWordCount>7946</pdfWordCount><pdfCharCount>50988</pdfCharCount><pdfVersion>1.3</pdfVersion><pdfPageCount>12</pdfPageCount><pdfPageSize>612 x 792 pts (letter)</pdfPageSize><refBibsNative>true</refBibsNative><abstractWordCount>119</abstractWordCount><abstractCharCount>858</abstractCharCount><keywordCount>0</keywordCount></qualityIndicators><title>Oligomeric Rings of the Sec61p Complex Induced by Ligands Required for Protein Translocation</title><pmid><json:string>8929540</json:string></pmid><pii><json:string>S0092-8674(00)81391-4</json:string></pii><genre><json:string>research-article</json:string></genre><host><title>Cell</title><language><json:string>unknown</json:string></language><publicationDate>1996</publicationDate><issn><json:string>0092-8674</json:string></issn><pii><json:string>S0092-8674(00)X0105-5</json:string></pii><volume>87</volume><issue>4</issue><pages><first>721</first><last>732</last></pages><genre><json:string>journal</json:string></genre></host><namedEntities><unitex><date><json:string>55S</json:string><json:string>35S</json:string><json:string>1996</json:string></date><geogName></geogName><orgName><json:string>Fulbright Junior Research Program</json:string><json:string>Division of Biology</json:string><json:string>Max Delbrueck Center for Molecular Medicine Robert Roessle Str</json:string><json:string>Department of Cell Biology Harvard Medical School Boston, Massachusetts</json:string><json:string>Medicine Brown University</json:string><json:string>Brookhaven National Laboratory</json:string><json:string>NIH</json:string></orgName><orgName_funder><json:string>NIH</json:string></orgName_funder><orgName_provider></orgName_provider><persName><json:string>Christopher W. Akey</json:string><json:string>M. Rolls</json:string><json:string>Rhode Island</json:string><json:string>G. Sosinsky</json:string><json:string>P. Stein</json:string><json:string>A. Johnson</json:string><json:string>Kenneth R. Miller</json:string><json:string>A. Freeze</json:string><json:string>E. Bullitt</json:string><json:string>The</json:string><json:string>Tom A. Rapoport</json:string><json:string>E. Hartmann</json:string><json:string>M. Simon</json:string><json:string>J. Wall</json:string></persName><placeName></placeName><ref_url></ref_url><ref_bibl><json:string>Hartmann et al.</json:string><json:string>Deshaies and Schekman, 1987</json:string><json:string>Sanders et al.</json:string><json:string>Frank et al., 1996</json:string><json:string>Walter and Johnson, 1994</json:string><json:string>Rothblatt et al., 1989</json:string><json:string>Crowley et al., 1994</json:string><json:string>Wall and Hainfeld, 1986</json:string><json:string>Gorlich ¨ and Rapoport, 1993</json:string><json:string>Kellaris et al., 1991</json:string><json:string>Walter et al., 1981</json:string><json:string>Panzner et al., 1995</json:string><json:string>Giddings and Staehelin, 1980</json:string><json:string>Belin et al., 1996</json:string><json:string>Kalies et al., 1994</json:string><json:string>Finke et al. (1996)</json:string><json:string>Rapoport et al., 1996</json:string><json:string>Panzner et al. (1995)</json:string><json:string>Rapoport, 1985</json:string><json:string>Do et al., 1996</json:string><json:string>Frank et al., 1988</json:string><json:string>Walter and Blobel (1983)</json:string><json:string>Martoglio et al., 1995</json:string><json:string>Gor¨ lich and Rapoport, 1993</json:string><json:string>High et al., 1993</json:string><json:string>Gorlich and Rapoport, 1993</json:string><json:string>Nicchitta et al., 1995</json:string><json:string>Dubochet et al., 1988</json:string><json:string>Mothes et al., 1994</json:string><json:string>Kutay et al., 1995</json:string><json:string>Akey, 1995</json:string><json:string>Musch et al., 1992</json:string><json:string>Ojakian et al., 1977</json:string><json:string>Hartmann et al., 1994</json:string><json:string>de-Castillia et al. (1995)</json:string><json:string>Gorlich et al., 1992</json:string><json:string>Simon and Blobel, 1991</json:string><json:string>Jungnickel and Rapoport, 1995</json:string><json:string>Deshaies and Kirschner (1995)</json:string><json:string>Kalies et al. (1994)</json:string><json:string>Blobel and Dobberstein, 1975</json:string><json:string>Singer et al., 1987</json:string><json:string>Crowley et al., 1993, 1994</json:string></ref_bibl><bibl></bibl></unitex></namedEntities><ark><json:string>ark:/67375/6H6-2LWHHVL0-5</json:string></ark><categories><wos><json:string>1 - science</json:string><json:string>2 - cell biology</json:string><json:string>2 - biochemistry & molecular biology</json:string></wos><scienceMetrix><json:string>1 - health sciences</json:string><json:string>2 - biomedical research</json:string><json:string>3 - developmental biology</json:string></scienceMetrix><scopus><json:string>1 - Life Sciences</json:string><json:string>2 - Biochemistry, Genetics and Molecular Biology</json:string><json:string>3 - General Biochemistry, Genetics and Molecular Biology</json:string></scopus><inist><json:string>1 - sciences appliquees, technologies et medecines</json:string><json:string>2 - sciences biologiques et medicales</json:string><json:string>3 - sciences biologiques fondamentales et appliquees. psychologie</json:string></inist></categories><publicationDate>1996</publicationDate><copyrightDate>1996</copyrightDate><doi><json:string>10.1016/S0092-8674(00)81391-4</json:string></doi><id>27D677446EBDA74678F1FCB925F938D7A7639226</id><score>1</score><fulltext><json:item><extension>pdf</extension><original>true</original><mimetype>application/pdf</mimetype><uri>https://api.istex.fr/ark:/67375/6H6-2LWHHVL0-5/fulltext.pdf</uri></json:item><json:item><extension>zip</extension><original>false</original><mimetype>application/zip</mimetype><uri>https://api.istex.fr/ark:/67375/6H6-2LWHHVL0-5/bundle.zip</uri></json:item><istex:fulltextTEI uri="https://api.istex.fr/ark:/67375/6H6-2LWHHVL0-5/fulltext.tei"><teiHeader><fileDesc><titleStmt><title level="a" type="main" xml:lang="en">Oligomeric Rings of the Sec61p Complex Induced by Ligands Required for Protein Translocation</title></titleStmt><publicationStmt><authority>ISTEX</authority><publisher scheme="https://scientific-publisher.data.istex.fr">ELSEVIER</publisher><availability><licence><p>©1996 Cell Press</p></licence><p scheme="https://loaded-corpus.data.istex.fr/ark:/67375/XBH-HKKZVM7B-M">elsevier</p></availability><date>1996</date></publicationStmt><notesStmt><note type="research-article" scheme="https://content-type.data.istex.fr/ark:/67375/XTP-1JC4F85T-7">research-article</note><note type="journal" scheme="https://publication-type.data.istex.fr/ark:/67375/JMC-0GLKJH51-B">journal</note><note type="content">Section title: Article</note><note type="content">Figure 1: Individual Images and Averaged Projection Maps of the Sec61p Complex (A) Individual particles of the canine Sec61p complex viewed in negative stain. (B) Averaged maps obtained using the corresponding single molecules of (A) as references. (C and D) Individual yeast Sec61p complexes and corresponding averages viewed in negative stain. (E and F) Individual frozen-hydrated particles of the canine Sec61p complex and corresponding averages. (G) Global average of all particles of canine Sec61p complex in negative stain (diameter of 83 Å with a central pore of 19 Å). (H) Global average of all particles of yeast Sec61p complex in negative stain (diameter of 82 Å with a central pore of 21 Å). (I) Global average of all particles of canine Sec61p complex in ice (diameter of 90 Å with a central pore of 23 Å). (J) A selected map obtained from classification analysis of the combined canine/yeast data sets in negative stain. The positions of consistent density peaks are shown with dark dots in (I) and (J). The number of particles analyzed is shown in the lower right-hand corner of (G)–(J).</note><note type="content">Figure 2: Negatively Stained Translocation Complexes (A) The trimeric canine Sec61p complex in a close-packed array. Particular examples of ring-like structures are indicated by arrowheads. Smaller molecular fragments can be seen between the rings. Inset: summed powder diffraction pattern from ∼2.5 × 105 oligomers, with a first order spacing of 1/97.5 Å. Scale bar = 500 Å. (B) The heptameric Sec complex from S. cerevisiae at low magnification (scale bar = 500 Å). Most particles are globular and do not show a ring morphology. (C) The Sec complex at higher magnification, scale as in (A): asymmetric complexes with stain-filled pores that are generally located off center (see arrowheads).</note><note type="content">Figure 3: Freeze-Fracture Micrographs of the Sec61p Complex in Reconstituted Proteoliposomes (A) Reconstituted canine Sec61p complex analyzed in the absence of ribosomes. The protein was reconstituted at ∼100 pmol/100 μg lipid or at ∼30 pmol/100 μg lipid (inset). (B) Reconstituted canine Sec61p complex (∼100 pmol/100 μg lipid) analyzed in the presence of wheat-germ ribosomes. The inset shows densely packed rings from a different specimen. (C) Reconstituted Sec61p complex from S. cerevisiae analyzed in the presence or absence (inset) of yeast ribosomes. (D) Reconstituted Sec61p complex from yeast, isolated from the dissociated heptameric Sec complex, analyzed in the presence or absence (inset) of yeast ribosomes. Scale bar = 500 Å.</note><note type="content">Figure 4: Freeze-Fracture Micrographs of the Heptameric Sec Complex from Yeast and Its Subcomplexes in Reconstituted Proteoliposomes (A) Reconstituted yeast Sec61p subcomplex, isolated from the dissociated heptameric Sec complex. (B) Reconstituted yeast Sec62/63p subcomplex, isolated upon dissociation of the heptameric Sec complex. (C) Coreconstitution of the yeast Sec61p and Sec62/63p subcomplexes. (D) Reconstitution of the native heptameric Sec complex. Scale bar = 500 Å.</note><note type="content">Figure 5: Freeze-Fracture Electron Micrographs of Native and Reconstituted Canine Microsomes (A) Freeze-fracture and deep-etch faces from RM reveal ring-like particles and ribosome surface “bumps” (white arrow labeled R). Many of the rings have a quasipentagonal morphology (see arrowheads in the inset). (B) Native microsomes stripped of ribosomes by treatment with puromycin/high salt. (C) Proteoliposomes reconstituted from a crude digitonin extract of ribosome-stripped microsomes. The sample was analyzed in the presence of wheat-germ ribosomes. (D) Proteoliposomes reconstituted from a crude extract that had been subjected to a mock depletion of the Sec61p complex. The sample was analyzed in the presence of wheat-germ ribosomes. (E) Proteoliposomes reconstituted from a crude extract that had been subjected to immunodepletion of the Sec61p complex. The sample was analyzed without ribosome addition. (F) Proteoliposomes reconstituted from a crude extract that had been subjected to immunodepletion of the Sec61p complex. The sample was analyzed in the presence of ribosomes. Scale bar = 500 Å.</note><note type="content">Figure 6: Freeze-Fracture Electron Micrographs of Yeast Nuclear Envelopes (A) Cytoplasmic surface of the yeast nuclear envelopes, as viewed by deep etching to reveal ribosome “bumps” (upper surface, see the white arrow labeled E). The lower surface shows a rare fracture that occurred close to the outer nuclear-envelope surface and thereby revealed the ribosomes (see the arrow labeled R). (B) A fracture plane revealing ring-like particles in the plane of the membrane. (A) and (B) are shown at the same scale (scale bar = 500 Å). (C) A magnified region of an internal fracture face of the nuclear envelope. The arrowheads point to typical ring-like structures. Scale bar = 500 Å.</note><note type="content">Figure 7: Model for the Role of an Oligomer of the Sec61p Complex in Protein Translocation Across the ER Membrane In the model shown, an equilibrium exists between monomeric and oligomeric Sec61p heterotrimers that favors monomers in the absence of the appropriate ligands. In the cotranslational pathway, the binding of the ribosome would stimulate assembly of oligomers. In the posttranslational pathway, the role of the ribosome would be replaced by the Sec62/63p complex. In both cases, the channel would initially be closed and only opened upon interaction with the signal sequence of a translocating polypeptide chain (gating). In an alternative model, the ribosome or the Sec62/63p complex would bind directly to a previously assembled Sec61p oligomer. The gating step would remain unchanged.</note><note type="content">Table 1: Particle Sizes in Freeze-Fractured Membranes</note></notesStmt><sourceDesc><biblStruct type="inbook"><analytic><title level="a" type="main" xml:lang="en">Oligomeric Rings of the Sec61p Complex Induced by Ligands Required for Protein Translocation</title><author xml:id="author-0000"><persName><forename type="first">Dorit</forename><surname>Hanein</surname></persName><affiliation>Department of Biophysics, Boston University School of Medicine, Boston, Massashusetts 02218-2394, USA</affiliation></author><author xml:id="author-0001"><persName><forename type="first">Kent E.S</forename><surname>Matlack</surname></persName><affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</affiliation></author><author xml:id="author-0002"><persName><forename type="first">Berit</forename><surname>Jungnickel</surname></persName><affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</affiliation></author><author xml:id="author-0003"><persName><forename type="first">Kathrin</forename><surname>Plath</surname></persName><affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</affiliation><affiliation>Max Delbrueck Center for Molecular Medicine, Robert Roessle Str. 10, 13122 Berlin-Buch, Germany</affiliation></author><author xml:id="author-0004"><persName><forename type="first">Kai-Uwe</forename><surname>Kalies</surname></persName><affiliation>Max Delbrueck Center for Molecular Medicine, Robert Roessle Str. 10, 13122 Berlin-Buch, Germany</affiliation></author><author xml:id="author-0005"><persName><forename type="first">Kenneth R</forename><surname>Miller</surname></persName><affiliation>Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912, USA</affiliation></author><author xml:id="author-0006"><persName><forename type="first">Tom A</forename><surname>Rapoport</surname></persName><affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</affiliation></author><author xml:id="author-0007"><persName><forename type="first">Christopher W</forename><surname>Akey</surname></persName><email>akey@med-biophm.bu.edu</email><affiliation>Department of Biophysics, Boston University School of Medicine, Boston, Massashusetts 02218-2394, USA</affiliation><affiliation>Correspondence: Christopher W. Akey, 617 638 4051 (phone), 617 638 4041 (fax)</affiliation></author><idno type="istex">27D677446EBDA74678F1FCB925F938D7A7639226</idno><idno type="ark">ark:/67375/6H6-2LWHHVL0-5</idno><idno type="DOI">10.1016/S0092-8674(00)81391-4</idno><idno type="PII">S0092-8674(00)81391-4</idno></analytic><monogr><title level="j">Cell</title><title level="j" type="abbrev">CELL</title><idno type="pISSN">0092-8674</idno><idno type="PII">S0092-8674(00)X0105-5</idno><imprint><publisher>ELSEVIER</publisher><date type="published" when="1996"></date><biblScope unit="volume">87</biblScope><biblScope unit="issue">4</biblScope><biblScope unit="page" from="721">721</biblScope><biblScope unit="page" to="732">732</biblScope></imprint></monogr></biblStruct></sourceDesc></fileDesc><profileDesc><creation><date>1996</date></creation><langUsage><language ident="en">en</language></langUsage><abstract xml:lang="en"><p>Abstract: The heterotrimeric Sec61p complex is a major component of the protein-conducting channel of the endoplasmic reticulum (ER) membrane, associating with either ribosomes or the Sec62/63 complex to perform co- and posttranslational transport, respectively. We show by electron microscopy that purified mammalian and yeast Sec61p complexes in detergent form cylindrical oligomers with a diameter of ∼85 Å and a central pore of ∼20 Å. Each oligomer contains 3–4 heterotrimers. Similar ring structures are seen in reconstituted proteoliposomes and native membranes. Oligomer formation by the reconstituted Sec61p complex is stimulated by its association with ribosomes or the Sec62/63p complex. We propose that these cylindrical oligomers represent protein-conducting channels of the ER, formed by ligands specific for co- and posttranslational transport.</p></abstract></profileDesc><revisionDesc><change when="1996-09-24">Modified</change><change when="1996">Published</change></revisionDesc></teiHeader></istex:fulltextTEI><json:item><extension>txt</extension><original>false</original><mimetype>text/plain</mimetype><uri>https://api.istex.fr/ark:/67375/6H6-2LWHHVL0-5/fulltext.txt</uri></json:item></fulltext><metadata><istex:metadataXml wicri:clean="Elsevier, elements deleted: ce:floats; body; tail"><istex:xmlDeclaration>version="1.0" encoding="utf-8"</istex:xmlDeclaration><istex:docType PUBLIC="-//ES//DTD journal article DTD version 4.5.2//EN//XML" URI="art452.dtd" name="istex:docType"><istex:entity SYSTEM="gr1" NDATA="IMAGE" name="gr1"></istex:entity><istex:entity SYSTEM="gr2" NDATA="IMAGE" name="gr2"></istex:entity><istex:entity SYSTEM="gr3" NDATA="IMAGE" name="gr3"></istex:entity><istex:entity SYSTEM="gr4" NDATA="IMAGE" name="gr4"></istex:entity><istex:entity SYSTEM="gr5" NDATA="IMAGE" name="gr5"></istex:entity><istex:entity SYSTEM="gr6" NDATA="IMAGE" name="gr6"></istex:entity><istex:entity SYSTEM="gr7" NDATA="IMAGE" name="gr7"></istex:entity></istex:docType><istex:document><converted-article version="4.5.2" docsubtype="fla" xml:lang="en"><item-info><jid>CELL</jid><aid>912</aid><ce:pii>S0092-8674(00)81391-4</ce:pii><ce:doi>10.1016/S0092-8674(00)81391-4</ce:doi><ce:copyright type="other" year="1996">Cell Press</ce:copyright></item-info><head><ce:dochead><ce:textfn>Article</ce:textfn></ce:dochead><ce:title>Oligomeric Rings of the Sec61p Complex Induced by Ligands Required for Protein Translocation</ce:title><ce:author-group><ce:author><ce:given-name>Dorit</ce:given-name><ce:surname>Hanein</ce:surname><ce:cross-ref refid="AFF1"><ce:sup>1</ce:sup></ce:cross-ref></ce:author><ce:author><ce:given-name>Kent E.S</ce:given-name><ce:surname>Matlack</ce:surname><ce:cross-ref refid="AFF2"><ce:sup>2</ce:sup></ce:cross-ref></ce:author><ce:author><ce:given-name>Berit</ce:given-name><ce:surname>Jungnickel</ce:surname><ce:cross-ref refid="AFF2"><ce:sup>2</ce:sup></ce:cross-ref></ce:author><ce:author><ce:given-name>Kathrin</ce:given-name><ce:surname>Plath</ce:surname><ce:cross-ref refid="AFF2"><ce:sup>2</ce:sup></ce:cross-ref><ce:cross-ref refid="AFF3"><ce:sup>3</ce:sup></ce:cross-ref></ce:author><ce:author><ce:given-name>Kai-Uwe</ce:given-name><ce:surname>Kalies</ce:surname><ce:cross-ref refid="AFF3"><ce:sup>3</ce:sup></ce:cross-ref></ce:author><ce:author><ce:given-name>Kenneth R</ce:given-name><ce:surname>Miller</ce:surname><ce:cross-ref refid="AFF4"><ce:sup>4</ce:sup></ce:cross-ref></ce:author><ce:author><ce:given-name>Tom A</ce:given-name><ce:surname>Rapoport</ce:surname><ce:cross-ref refid="AFF2"><ce:sup>2</ce:sup></ce:cross-ref></ce:author><ce:author><ce:given-name>Christopher W</ce:given-name><ce:surname>Akey</ce:surname><ce:cross-ref refid="AFF1"><ce:sup>1</ce:sup></ce:cross-ref><ce:cross-ref refid="COR1">*</ce:cross-ref><ce:e-address>akey@med-biophm.bu.edu</ce:e-address></ce:author><ce:affiliation id="AFF1"><ce:label>1</ce:label><ce:textfn>Department of Biophysics, Boston University School of Medicine, Boston, Massashusetts 02218-2394, USA</ce:textfn></ce:affiliation><ce:affiliation id="AFF2"><ce:label>2</ce:label><ce:textfn>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</ce:textfn></ce:affiliation><ce:affiliation id="AFF3"><ce:label>3</ce:label><ce:textfn>Max Delbrueck Center for Molecular Medicine, Robert Roessle Str. 10, 13122 Berlin-Buch, Germany</ce:textfn></ce:affiliation><ce:affiliation id="AFF4"><ce:label>4</ce:label><ce:textfn>Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912, USA</ce:textfn></ce:affiliation><ce:correspondence id="COR1"><ce:label>*</ce:label><ce:text>Correspondence: Christopher W. Akey, 617 638 4051 (phone), 617 638 4041 (fax)</ce:text></ce:correspondence></ce:author-group><ce:date-received day="22" month="8" year="1996"></ce:date-received><ce:date-revised day="24" month="9" year="1996"></ce:date-revised><ce:abstract><ce:section-title>Abstract</ce:section-title><ce:abstract-sec><ce:simple-para>The heterotrimeric Sec61p complex is a major component of the protein-conducting channel of the endoplasmic reticulum (ER) membrane, associating with either ribosomes or the Sec62/63 complex to perform co- and posttranslational transport, respectively. We show by electron microscopy that purified mammalian and yeast Sec61p complexes in detergent form cylindrical oligomers with a diameter of ∼85 Å and a central pore of ∼20 Å. Each oligomer contains 3–4 heterotrimers. Similar ring structures are seen in reconstituted proteoliposomes and native membranes. Oligomer formation by the reconstituted Sec61p complex is stimulated by its association with ribosomes or the Sec62/63p complex. We propose that these cylindrical oligomers represent protein-conducting channels of the ER, formed by ligands specific for co- and posttranslational transport.</ce:simple-para></ce:abstract-sec></ce:abstract></head></converted-article></istex:document></istex:metadataXml><mods version="3.6"><titleInfo lang="en"><title>Oligomeric Rings of the Sec61p Complex Induced by Ligands Required for Protein Translocation</title></titleInfo><titleInfo type="alternative" lang="en" contentType="CDATA"><title>Oligomeric Rings of the Sec61p Complex Induced by Ligands Required for Protein Translocation</title></titleInfo><name type="personal"><namePart type="given">Dorit</namePart><namePart type="family">Hanein</namePart><affiliation>Department of Biophysics, Boston University School of Medicine, Boston, Massashusetts 02218-2394, USA</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">Kent E.S</namePart><namePart type="family">Matlack</namePart><affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">Berit</namePart><namePart type="family">Jungnickel</namePart><affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">Kathrin</namePart><namePart type="family">Plath</namePart><affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</affiliation><affiliation>Max Delbrueck Center for Molecular Medicine, Robert Roessle Str. 10, 13122 Berlin-Buch, Germany</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">Kai-Uwe</namePart><namePart type="family">Kalies</namePart><affiliation>Max Delbrueck Center for Molecular Medicine, Robert Roessle Str. 10, 13122 Berlin-Buch, Germany</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">Kenneth R</namePart><namePart type="family">Miller</namePart><affiliation>Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912, USA</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">Tom A</namePart><namePart type="family">Rapoport</namePart><affiliation>Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">Christopher W</namePart><namePart type="family">Akey</namePart><affiliation>Department of Biophysics, Boston University School of Medicine, Boston, Massashusetts 02218-2394, USA</affiliation><affiliation>Correspondence: Christopher W. Akey, 617 638 4051 (phone), 617 638 4041 (fax)</affiliation><affiliation>E-mail: akey@med-biophm.bu.edu</affiliation><role><roleTerm type="text">author</roleTerm></role></name><typeOfResource>text</typeOfResource><genre type="research-article" displayLabel="Full-length article" authority="ISTEX" authorityURI="https://content-type.data.istex.fr" valueURI="https://content-type.data.istex.fr/ark:/67375/XTP-1JC4F85T-7">research-article</genre><originInfo><publisher>ELSEVIER</publisher><dateIssued encoding="w3cdtf">1996</dateIssued><dateModified encoding="w3cdtf">1996-09-24</dateModified><copyrightDate encoding="w3cdtf">1996</copyrightDate></originInfo><language><languageTerm type="code" authority="iso639-2b">eng</languageTerm><languageTerm type="code" authority="rfc3066">en</languageTerm></language><abstract lang="en">Abstract: The heterotrimeric Sec61p complex is a major component of the protein-conducting channel of the endoplasmic reticulum (ER) membrane, associating with either ribosomes or the Sec62/63 complex to perform co- and posttranslational transport, respectively. We show by electron microscopy that purified mammalian and yeast Sec61p complexes in detergent form cylindrical oligomers with a diameter of ∼85 Å and a central pore of ∼20 Å. Each oligomer contains 3–4 heterotrimers. Similar ring structures are seen in reconstituted proteoliposomes and native membranes. Oligomer formation by the reconstituted Sec61p complex is stimulated by its association with ribosomes or the Sec62/63p complex. We propose that these cylindrical oligomers represent protein-conducting channels of the ER, formed by ligands specific for co- and posttranslational transport.</abstract><note type="content">Section title: Article</note><note type="content">Figure 1: Individual Images and Averaged Projection Maps of the Sec61p Complex (A) Individual particles of the canine Sec61p complex viewed in negative stain. (B) Averaged maps obtained using the corresponding single molecules of (A) as references. (C and D) Individual yeast Sec61p complexes and corresponding averages viewed in negative stain. (E and F) Individual frozen-hydrated particles of the canine Sec61p complex and corresponding averages. (G) Global average of all particles of canine Sec61p complex in negative stain (diameter of 83 Å with a central pore of 19 Å). (H) Global average of all particles of yeast Sec61p complex in negative stain (diameter of 82 Å with a central pore of 21 Å). (I) Global average of all particles of canine Sec61p complex in ice (diameter of 90 Å with a central pore of 23 Å). (J) A selected map obtained from classification analysis of the combined canine/yeast data sets in negative stain. The positions of consistent density peaks are shown with dark dots in (I) and (J). The number of particles analyzed is shown in the lower right-hand corner of (G)–(J).</note><note type="content">Figure 2: Negatively Stained Translocation Complexes (A) The trimeric canine Sec61p complex in a close-packed array. Particular examples of ring-like structures are indicated by arrowheads. Smaller molecular fragments can be seen between the rings. Inset: summed powder diffraction pattern from ∼2.5 × 105 oligomers, with a first order spacing of 1/97.5 Å. Scale bar = 500 Å. (B) The heptameric Sec complex from S. cerevisiae at low magnification (scale bar = 500 Å). Most particles are globular and do not show a ring morphology. (C) The Sec complex at higher magnification, scale as in (A): asymmetric complexes with stain-filled pores that are generally located off center (see arrowheads).</note><note type="content">Figure 3: Freeze-Fracture Micrographs of the Sec61p Complex in Reconstituted Proteoliposomes (A) Reconstituted canine Sec61p complex analyzed in the absence of ribosomes. The protein was reconstituted at ∼100 pmol/100 μg lipid or at ∼30 pmol/100 μg lipid (inset). (B) Reconstituted canine Sec61p complex (∼100 pmol/100 μg lipid) analyzed in the presence of wheat-germ ribosomes. The inset shows densely packed rings from a different specimen. (C) Reconstituted Sec61p complex from S. cerevisiae analyzed in the presence or absence (inset) of yeast ribosomes. (D) Reconstituted Sec61p complex from yeast, isolated from the dissociated heptameric Sec complex, analyzed in the presence or absence (inset) of yeast ribosomes. Scale bar = 500 Å.</note><note type="content">Figure 4: Freeze-Fracture Micrographs of the Heptameric Sec Complex from Yeast and Its Subcomplexes in Reconstituted Proteoliposomes (A) Reconstituted yeast Sec61p subcomplex, isolated from the dissociated heptameric Sec complex. (B) Reconstituted yeast Sec62/63p subcomplex, isolated upon dissociation of the heptameric Sec complex. (C) Coreconstitution of the yeast Sec61p and Sec62/63p subcomplexes. (D) Reconstitution of the native heptameric Sec complex. Scale bar = 500 Å.</note><note type="content">Figure 5: Freeze-Fracture Electron Micrographs of Native and Reconstituted Canine Microsomes (A) Freeze-fracture and deep-etch faces from RM reveal ring-like particles and ribosome surface “bumps” (white arrow labeled R). Many of the rings have a quasipentagonal morphology (see arrowheads in the inset). (B) Native microsomes stripped of ribosomes by treatment with puromycin/high salt. (C) Proteoliposomes reconstituted from a crude digitonin extract of ribosome-stripped microsomes. The sample was analyzed in the presence of wheat-germ ribosomes. (D) Proteoliposomes reconstituted from a crude extract that had been subjected to a mock depletion of the Sec61p complex. The sample was analyzed in the presence of wheat-germ ribosomes. (E) Proteoliposomes reconstituted from a crude extract that had been subjected to immunodepletion of the Sec61p complex. The sample was analyzed without ribosome addition. (F) Proteoliposomes reconstituted from a crude extract that had been subjected to immunodepletion of the Sec61p complex. The sample was analyzed in the presence of ribosomes. Scale bar = 500 Å.</note><note type="content">Figure 6: Freeze-Fracture Electron Micrographs of Yeast Nuclear Envelopes (A) Cytoplasmic surface of the yeast nuclear envelopes, as viewed by deep etching to reveal ribosome “bumps” (upper surface, see the white arrow labeled E). The lower surface shows a rare fracture that occurred close to the outer nuclear-envelope surface and thereby revealed the ribosomes (see the arrow labeled R). (B) A fracture plane revealing ring-like particles in the plane of the membrane. (A) and (B) are shown at the same scale (scale bar = 500 Å). (C) A magnified region of an internal fracture face of the nuclear envelope. The arrowheads point to typical ring-like structures. Scale bar = 500 Å.</note><note type="content">Figure 7: Model for the Role of an Oligomer of the Sec61p Complex in Protein Translocation Across the ER Membrane In the model shown, an equilibrium exists between monomeric and oligomeric Sec61p heterotrimers that favors monomers in the absence of the appropriate ligands. In the cotranslational pathway, the binding of the ribosome would stimulate assembly of oligomers. In the posttranslational pathway, the role of the ribosome would be replaced by the Sec62/63p complex. In both cases, the channel would initially be closed and only opened upon interaction with the signal sequence of a translocating polypeptide chain (gating). In an alternative model, the ribosome or the Sec62/63p complex would bind directly to a previously assembled Sec61p oligomer. The gating step would remain unchanged.</note><note type="content">Table 1: Particle Sizes in Freeze-Fractured Membranes</note><relatedItem type="host"><titleInfo><title>Cell</title></titleInfo><titleInfo type="abbreviated"><title>CELL</title></titleInfo><genre type="journal" authority="ISTEX" authorityURI="https://publication-type.data.istex.fr" valueURI="https://publication-type.data.istex.fr/ark:/67375/JMC-0GLKJH51-B">journal</genre><originInfo><publisher>ELSEVIER</publisher><dateIssued encoding="w3cdtf">1996</dateIssued></originInfo><identifier type="ISSN">0092-8674</identifier><identifier type="PII">S0092-8674(00)X0105-5</identifier><part><date>1996</date><detail type="volume"><number>87</number><caption>vol.</caption></detail><detail type="issue"><number>4</number><caption>no.</caption></detail><extent unit="issue-pages"><start>589</start><end>777</end></extent><extent unit="pages"><start>721</start><end>732</end></extent></part></relatedItem><identifier type="istex">27D677446EBDA74678F1FCB925F938D7A7639226</identifier><identifier type="ark">ark:/67375/6H6-2LWHHVL0-5</identifier><identifier type="DOI">10.1016/S0092-8674(00)81391-4</identifier><identifier type="PII">S0092-8674(00)81391-4</identifier><accessCondition type="use and reproduction" contentType="copyright">©1996 Cell Press</accessCondition><recordInfo><recordContentSource authority="ISTEX" authorityURI="https://loaded-corpus.data.istex.fr" valueURI="https://loaded-corpus.data.istex.fr/ark:/67375/XBH-HKKZVM7B-M">elsevier</recordContentSource><recordOrigin>Cell Press, ©1996</recordOrigin></recordInfo></mods><json:item><extension>json</extension><original>false</original><mimetype>application/json</mimetype><uri>https://api.istex.fr/ark:/67375/6H6-2LWHHVL0-5/record.json</uri></json:item></metadata><serie></serie></istex></record>Pour manipuler ce document sous Unix (Dilib)
EXPLOR_STEP=$WICRI_ROOT/Sante/explor/MersV1/Data/Istex/Corpus
HfdSelect -h $EXPLOR_STEP/biblio.hfd -nk 002689 | SxmlIndent | more
Ou
HfdSelect -h $EXPLOR_AREA/Data/Istex/Corpus/biblio.hfd -nk 002689 | SxmlIndent | more
Pour mettre un lien sur cette page dans le réseau Wicri
{{Explor lien
|wiki= Sante
|area= MersV1
|flux= Istex
|étape= Corpus
|type= RBID
|clé= ISTEX:27D677446EBDA74678F1FCB925F938D7A7639226
|texte= Oligomeric Rings of the Sec61p Complex Induced by Ligands Required for Protein Translocation
}}
| This area was generated with Dilib version V0.6.33. |  |