title: Identification of Sec36p, Sec37p, and Sec38p: components of yeast complex that contains Sec34p and Sec35p.
abstract: The Saccharomyces cerevisiae proteins Sec34p and Sec35p are components of a large cytosolic complex involved in protein transport through the secretory pathway. Characterization of a new secretion mutant led us to identify SEC36, which encodes a new component of this complex. Sec36p binds to Sec34p and Sec35p, and mutation of SEC36 disrupts the complex, as determined by gel filtration. Missense mutations of SEC36 are lethal with mutations in COPI subunits, indicating a functional connection between the Sec34p/sec35p complex and the COPI vesicle coat. Affinity purification of proteins that bind to Sec35p-myc allowed identification of two additional proteins in the complex. We call these two conserved proteins Sec37p and Sec38p. Disruption of either SEC37 or SEC38 affects the size of the complex that contains Sec34p and Sec35p. We also examined COD4, COD5, and DOR1, three genes recently reported to encode proteins that bind to Sec35p. Each of the eight genes that encode components of the Sec34p/sec35p complex was tested for its contribution to cell growth, protein transport, and the integrity of the complex. These tests indicate two general types of subunits: Sec34p, Sec35p, Sec36p, and Sec38p seem to form the essential core of a complex to which Sec37p, Cod4p, Cod5p, and Dor1p seem to be peripherally attached.
authors: Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA.
authors: Rachna J
authors: RJ
authors: Ram
authors: Baojie
authors: B
authors: Li
authors: Chris A
authors: CA
authors: Kaiser
mesh_terms: D033942:Adaptor Proteins, Vesicular Transport; D002352:Carrier Proteins / Q000032:analysis / Q000235:genetics*; D020755:Coat Protein Complex I / Q000235:genetics; D017124:Conserved Sequence; D005656:Fungal Proteins / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism; D046911:Macromolecular Substances; D013058:Mass Spectrometry; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D026901:Membrane Transport Proteins; D009154:Mutation; D016366:Open Reading Frames; D011233:Precipitin Tests; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D033921:Vesicular Transport Proteins; D043324:beta-Fructofuranosidase
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; C112749:COG2 protein, S cerevisiae; C401396:COG3 protein, S cerevisiae; C468122:COG4 protein, S cerevisiae; C439910:COG8 protein, S cerevisiae; D002352:Carrier Proteins; D020755:Coat Protein Complex I; D005656:Fungal Proteins; C066709:GAS1 protein, S cerevisiae; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase