Skip to main content
PMC home page
Molecular Biology of the Cell logoLink to Molecular Biology of the Cell
. 1996 Nov;7(11):1815–1823. doi: 10.1091/mbc.7.11.1815

COPII coat subunit interactions: Sec24p and Sec23p bind to adjacent regions of Sec16p.

R E Gimeno 1, P Espenshade 1, C A Kaiser 1
PMCID: PMC276028  PMID: 8930902

Abstract

Formation of COPII-coated vesicles at the endoplasmic reticulum (ER) requires assembly onto the membrane of five cytosolic coat proteins, Sec23p, Sec24p, Sec13p, Sec31p, and Sar1p. A sixth vesicle coat component, Sec16p, is tightly associated with the ER membrane and has been proposed to act as a scaffold for membrane association of the soluble coat proteins. We previously showed that Sec23p binds to the C-terminal region of Sec16p. Here we use two-hybrid and coprecipitation assays to demonstrate that the essential COPII protein Sec24p binds to the central region of Sec16p. In vitro reconstitution of binding with purified recombinant proteins demonstrates that the interaction of Sec24p with the central domain of Sec16p does not depend on the presence of Sec23p. However, Sec23p facilitates binding of Sec24p to Sec16p, and the three proteins can form a ternary complex in vitro. Truncations of Sec24p demonstrate that the N-terminal and C-terminal regions of Sec24p display different binding specificities. The C terminus binds to the central domain of Sec16p, whereas the N terminus of Sec24p binds to both the central domain of Sec16p and to Sec23p. These findings define binding to Sec16p as a new function for Sec24p and support the idea that Sec16p organizes assembly of the COPII coat.

Full text

PDF
1818

Images in this article

1819Image
on p.1819
1820Image
on p.1820
1821Image
on p.1821

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Barlowe C., Orci L., Yeung T., Hosobuchi M., Hamamoto S., Salama N., Rexach M. F., Ravazzola M., Amherdt M., Schekman R. COPII: a membrane coat formed by Sec proteins that drive vesicle budding from the endoplasmic reticulum. Cell. 1994 Jun 17;77(6):895–907. doi: 10.1016/0092-8674(94)90138-4. [DOI] [PubMed] [Google Scholar]
  2. Bartel P. L., Fields S. Analyzing protein-protein interactions using two-hybrid system. Methods Enzymol. 1995;254:241–263. doi: 10.1016/0076-6879(95)54018-0. [DOI] [PubMed] [Google Scholar]
  3. Donaldson J. G., Finazzi D., Klausner R. D. Brefeldin A inhibits Golgi membrane-catalysed exchange of guanine nucleotide onto ARF protein. Nature. 1992 Nov 26;360(6402):350–352. doi: 10.1038/360350a0. [DOI] [PubMed] [Google Scholar]
  4. Espenshade P., Gimeno R. E., Holzmacher E., Teung P., Kaiser C. A. Yeast SEC16 gene encodes a multidomain vesicle coat protein that interacts with Sec23p. J Cell Biol. 1995 Oct;131(2):311–324. doi: 10.1083/jcb.131.2.311. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Fields S., Song O. A novel genetic system to detect protein-protein interactions. Nature. 1989 Jul 20;340(6230):245–246. doi: 10.1038/340245a0. [DOI] [PubMed] [Google Scholar]
  6. Gimeno R. E., Espenshade P., Kaiser C. A. SED4 encodes a yeast endoplasmic reticulum protein that binds Sec16p and participates in vesicle formation. J Cell Biol. 1995 Oct;131(2):325–338. doi: 10.1083/jcb.131.2.325. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Golemis E. A., Brent R. Fused protein domains inhibit DNA binding by LexA. Mol Cell Biol. 1992 Jul;12(7):3006–3014. doi: 10.1128/mcb.12.7.3006. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Gyuris J., Golemis E., Chertkov H., Brent R. Cdi1, a human G1 and S phase protein phosphatase that associates with Cdk2. Cell. 1993 Nov 19;75(4):791–803. doi: 10.1016/0092-8674(93)90498-f. [DOI] [PubMed] [Google Scholar]
  9. Hannon G. J., Demetrick D., Beach D. Isolation of the Rb-related p130 through its interaction with CDK2 and cyclins. Genes Dev. 1993 Dec;7(12A):2378–2391. doi: 10.1101/gad.7.12a.2378. [DOI] [PubMed] [Google Scholar]
  10. Helms J. B., Palmer D. J., Rothman J. E. Two distinct populations of ARF bound to Golgi membranes. J Cell Biol. 1993 May;121(4):751–760. doi: 10.1083/jcb.121.4.751. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Hicke L., Schekman R. Yeast Sec23p acts in the cytoplasm to promote protein transport from the endoplasmic reticulum to the Golgi complex in vivo and in vitro. EMBO J. 1989 Jun;8(6):1677–1684. doi: 10.1002/j.1460-2075.1989.tb03559.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Hicke L., Yoshihisa T., Schekman R. Sec23p and a novel 105-kDa protein function as a multimeric complex to promote vesicle budding and protein transport from the endoplasmic reticulum. Mol Biol Cell. 1992 Jun;3(6):667–676. doi: 10.1091/mbc.3.6.667. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Kaiser C. A., Schekman R. Distinct sets of SEC genes govern transport vesicle formation and fusion early in the secretory pathway. Cell. 1990 May 18;61(4):723–733. doi: 10.1016/0092-8674(90)90483-u. [DOI] [PubMed] [Google Scholar]
  14. Nakańo A., Muramatsu M. A novel GTP-binding protein, Sar1p, is involved in transport from the endoplasmic reticulum to the Golgi apparatus. J Cell Biol. 1989 Dec;109(6 Pt 1):2677–2691. doi: 10.1083/jcb.109.6.2677. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Salama N. R., Yeung T., Schekman R. W. The Sec13p complex and reconstitution of vesicle budding from the ER with purified cytosolic proteins. EMBO J. 1993 Nov;12(11):4073–4082. doi: 10.1002/j.1460-2075.1993.tb06091.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Schekman R., Orci L. Coat proteins and vesicle budding. Science. 1996 Mar 15;271(5255):1526–1533. doi: 10.1126/science.271.5255.1526. [DOI] [PubMed] [Google Scholar]
  17. Sikorski R. S., Hieter P. A system of shuttle vectors and yeast host strains designed for efficient manipulation of DNA in Saccharomyces cerevisiae. Genetics. 1989 May;122(1):19–27. doi: 10.1093/genetics/122.1.19. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Stamnes M. A., Rothman J. E. The binding of AP-1 clathrin adaptor particles to Golgi membranes requires ADP-ribosylation factor, a small GTP-binding protein. Cell. 1993 Jun 4;73(5):999–1005. doi: 10.1016/0092-8674(93)90277-w. [DOI] [PubMed] [Google Scholar]
  19. Thompson C. M., Koleske A. J., Chao D. M., Young R. A. A multisubunit complex associated with the RNA polymerase II CTD and TATA-binding protein in yeast. Cell. 1993 Jul 2;73(7):1361–1375. doi: 10.1016/0092-8674(93)90362-t. [DOI] [PubMed] [Google Scholar]
  20. Traub L. M., Ostrom J. A., Kornfeld S. Biochemical dissection of AP-1 recruitment onto Golgi membranes. J Cell Biol. 1993 Nov;123(3):561–573. doi: 10.1083/jcb.123.3.561. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Yoshihisa T., Barlowe C., Schekman R. Requirement for a GTPase-activating protein in vesicle budding from the endoplasmic reticulum. Science. 1993 Mar 5;259(5100):1466–1468. doi: 10.1126/science.8451644. [DOI] [PubMed] [Google Scholar]

Articles from Molecular Biology of the Cell are provided here courtesy of American Society for Cell Biology

RESOURCES