Subunit Structure of the Mammalian Exocyst Complex

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 94; no. 26; pp. 14438 - 14443
• Main Authors: Kee, Y, Yoo, J S, Hazuka, C D, Peterson, K E, Hsu, S C, Scheller, R H
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 23.12.1997; National Acad Sciences; National Academy of Sciences; The National Academy of Sciences of the USA
• Subjects: Amino Acid Sequence; Amino acids; Animals; Biological Sciences; Cell Membrane - metabolism; Cell membranes; Cellular biology; Cloning, Molecular; Complementary DNA; Deoxyribonucleic acid; DNA; DNA, Complementary - genetics; DNA, Complementary - isolation & purification; Exocytosis; Exocytosis - genetics; Genes; Mammals; Membrane Proteins - genetics; Membrane Proteins - metabolism; Messenger RNA; Molecular Sequence Data; PC12 cells; Proteins; Secretion; Sequence Alignment; SNARE proteins; Vesicular Transport Proteins; Yeast; Yeasts
• DOI: 10.1073/pnas.94.26.14438
• ISSN: 0027-8424

The exocyst is a protein complex required for the late stages of secretion in yeast. Unlike the SNAREs (SNAP receptors), important secretory proteins that are broadly distributed on the target membrane, the exocyst is specifically located at sites of vesicle fusion. We have isolated cDNAs encoding the rexo70, rsec5, and rsec15 subunits of the mammalian complex. The amino acid sequences encoded by these genes are between 21% and 24% identical to their yeast homologs. All three genes are broadly expressed and multiple transcripts are observed for rexo70 and rsec15. Characterization of cDNAs encoding the 84-kDa subunit of the mammalian complex revealed a novel protein. mAbs were generated to the mammalian rsec6 subunit of the exocyst complex. rsec6 immunoreactivity is found in a punctate distribution at terminals of PC12 cell processes at or near sites of granule exocytosis.