Yeast Sec proteins interact with polypeptides traversing the endoplasmic reticulum membrane.
We show by photocross-linking that nascent secretory proteins, during their passage through the endoplasmic reticulum membrane of S. cerevisiae, are in physical contact with Sec61p and Sec62p, two genetically identified membrane proteins that are essential for in vivo translocation. Sec61p seems to be in continuous contact, whereas Sec62p is involved only transiently. Translocation comprises both ATP-dependent and -independent phases of interaction with the Sec proteins. The results suggest a direct role of the Sec proteins in translocation.
Müsch
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Max-Delbrück-Center for Molecular Medicine, Berlin Buch, Germany.
Wiedmann
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Rapoport
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D000255:Adenosine Triphosphate / Q000378:metabolism; D000906:Antibodies; D001692:Biological Transport; D004721:Endoplasmic Reticulum / Q000737:chemistry / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D026901:Membrane Transport Proteins; D010455:Peptides / Q000378:metabolism*; D011691:Puromycin / Q000494:pharmacology; D000069816:SEC Translocation Channels; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins
D000906:Antibodies; D005656:Fungal Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D010455:Peptides; D000069816:SEC Translocation Channels; C499383:SEC61 protein, S cerevisiae; C074213:SEC62 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D011691:Puromycin; D000255:Adenosine Triphosphate