The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)



Gene Review

SEC1  -  Sec1p

Saccharomyces cerevisiae S288c

Synonyms: Protein transport protein SEC1, YD8358.18C, YDR164C
Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

High impact information on SEC1

  • VPS33B encodes a homolog of the class C yeast vacuolar protein sorting gene, Vps33, that contains a Sec1-like domain important in the regulation of vesicle-to-target SNARE complex formation and subsequent membrane fusion [1].
  • This mechanism likely involves the Sec1 homolog Sly1, which we identified in isolated docking complexes [2].
  • These data suggest that a member of the Sec1p class of proteins has an in vivo function in both general secretion and synaptic transmission [3].
  • The Sec1p/Munc18 protein Vps45p binds its cognate SNARE proteins via two distinct modes [4].
  • Functional specialization within a vesicle tethering complex: bypass of a subset of exocyst deletion mutants by Sec1p or Sec4p [5].

Biological context of SEC1


Anatomical context of SEC1


Associations of SEC1 with chemical compounds

  • Two temperature-conditional secretory mutations, sec1 and sec5, cause the accumulation of post-Golgi vesicles when strains containing these mutations are grown at 37 degrees C. In addition to accumulating vesicles, the mutants do not esterify free sterol on rich media at the restrictive temperature [13].
  • When grown at 37 degrees C on defined medium, the strains with sec5 or sec1 accumulated the usual secretory vesicles, but when grown under similar conditions with elevated levels of inositol, accumulated an additional vesicular-like body [13].
  • Assembly of v-SNARE-t-SNARE targeting complexes is modulated by members of the Sec1-Sly1 protein family, and by small guanosine triphosphatases termed Rabs [14].
  • Several of the encoded proteins, including Pep12p/Vps6p (an endosomal target (t) SNARE) and Vps45p (a Sec1p homologue), bind each other directly [1] [15].
  • The phosphatidylinositol 3-phosphate binding protein Vac1p interacts with a Rab GTPase and a Sec1p homologue to facilitate vesicle-mediated vacuolar protein sorting [16].

Physical interactions of SEC1

  • We further found that Mso1p interacts with Sec1p both in vitro and in the two-hybrid system [10].
  • Cytoplasm to vacuole trafficking of aminopeptidase I requires a t-SNARE-Sec1p complex composed of Tlg2p and Vps45p [17].
  • In experiments with purified proteins, we now made the observation that the ER to Golgi core SNARE fusion complex could be assembled on syntaxin Sed5p tightly bound to the Sec1-related Sly1p [18].

Regulatory relationships of SEC1

  • After inactivation of clathrin heavy chain, vacuolar protease-dependent degradation of all forms of Kex2p was blocked by a sec1 mutation, which is required for secretory vesicle fusion to the plasma membrane, indicating that transport to the cell surface was required for degradation by vacuolar proteolysis [9].
  • When expressed from the GAL1 promoter, RHO3 suppressed the growth defect of sec1 at the restrictive temperature and inhibited the growth of sec3-101 at the permissive temperature [19].
  • Genetic studies suggest that Mso1 enhances Sec1 function while attenuating Sec4 GTPase function [20].

Other interactions of SEC1

  • Mutation of SEC1, SEC4, or SEC8 blocked spore formation, and electron microscopic analysis of the sec4-8 mutant indicated that this inability to produce spores was caused by a failure to form the prospore membrane [21].
  • Loss of function mutations in SEC1, SLY1, or SLP1 result in blocking of protein transport between distinct yeast sub-cellular compartments [22].
  • The ypt31/32 phenotype is epistatic to that of a sec1 mutant, which accumulates secretory vesicles [23].
  • In addition, when vps8 mutants are combined with endocytic or late secretory pathway mutants (end3 or sec1, respectively), ALP is still delivered to the vacuole [24].
  • Saccharomyces cerevisiae Sly1 protein is a member of the Sec1/Munc18-family proteins, which are essential for vesicular trafficking, but their exact biological roles are yet to be determined [25].

Analytical, diagnostic and therapeutic context of SEC1


  1. Mutations in VPS33B, encoding a regulator of SNARE-dependent membrane fusion, cause arthrogryposis-renal dysfunction-cholestasis (ARC) syndrome. Gissen, P., Johnson, C.A., Morgan, N.V., Stapelbroek, J.M., Forshew, T., Cooper, W.N., McKiernan, P.J., Klomp, L.W., Morris, A.A., Wraith, J.E., McClean, P., Lynch, S.A., Thompson, R.J., Lo, B., Quarrell, O.W., Di Rocco, M., Trembath, R.C., Mandel, H., Wali, S., Karet, F.E., Knisely, A.S., Houwen, R.H., Kelly, D.A., Maher, E.R. Nat. Genet. (2004) [Pubmed]
  2. A rab protein is required for the assembly of SNARE complexes in the docking of transport vesicles. Søgaard, M., Tani, K., Ye, R.R., Geromanos, S., Tempst, P., Kirchhausen, T., Rothman, J.E., Söllner, T. Cell (1994) [Pubmed]
  3. Mutations in the Drosophila Rop gene suggest a function in general secretion and synaptic transmission. Harrison, S.D., Broadie, K., van de Goor, J., Rubin, G.M. Neuron (1994) [Pubmed]
  4. The Sec1p/Munc18 protein Vps45p binds its cognate SNARE proteins via two distinct modes. Carpp, L.N., Ciufo, L.F., Shanks, S.G., Boyd, A., Bryant, N.J. J. Cell Biol. (2006) [Pubmed]
  5. Functional specialization within a vesicle tethering complex: bypass of a subset of exocyst deletion mutants by Sec1p or Sec4p. Wiederkehr, A., De Craene, J.O., Ferro-Novick, S., Novick, P. J. Cell Biol. (2004) [Pubmed]
  6. Mutations in the VPS45 gene, a SEC1 homologue, result in vacuolar protein sorting defects and accumulation of membrane vesicles. Cowles, C.R., Emr, S.D., Horazdovsky, B.F. J. Cell. Sci. (1994) [Pubmed]
  7. Cloning and sequencing of the yeast Saccharomyces cerevisiae SEC1 gene localized on chromosome IV. Aalto, M.K., Ruohonen, L., Hosono, K., Keränen, S. Yeast (1991) [Pubmed]
  8. Molecular interactions position Mso1p, a novel PTB domain homologue, in the interface of the exocyst complex and the exocytic SNARE machinery in yeast. Knop, M., Miller, K.J., Mazza, M., Feng, D., Weber, M., Keränen, S., Jäntti, J. Mol. Biol. Cell (2005) [Pubmed]
  9. The effects of clathrin inactivation on localization of Kex2 protease are independent of the TGN localization signal in the cytosolic tail of Kex2p. Redding, K., Seeger, M., Payne, G.S., Fuller, R.S. Mol. Biol. Cell (1996) [Pubmed]
  10. Mso1p: a yeast protein that functions in secretion and interacts physically and genetically with Sec1p. Aalto, M.K., Jäntti, J., Ostling, J., Keränen, S., Ronne, H. Proc. Natl. Acad. Sci. U.S.A. (1997) [Pubmed]
  11. The Sec1/Munc18 protein, Vps33p, functions at the endosome and the vacuole of Saccharomyces cerevisiae. Subramanian, S., Woolford, C.A., Jones, E.W. Mol. Biol. Cell (2004) [Pubmed]
  12. An Arabidopsis VPS45p homolog implicated in protein transport to the vacuole. Bassham, D.C., Raikhel, N.V. Plant Physiol. (1998) [Pubmed]
  13. A conditional sterol esterification defect in yeast having either a sec1 or sec5 mutation in the secretory pathway. Tomeo, M.E., Palermo, L.M., Tove, S., Parks, L.W. Yeast (1997) [Pubmed]
  14. t-SNARE activation through transient interaction with a rab-like guanosine triphosphatase. Lupashin, V.V., Waters, M.G. Science (1997) [Pubmed]
  15. Vac1p coordinates Rab and phosphatidylinositol 3-kinase signaling in Vps45p-dependent vesicle docking/fusion at the endosome. Peterson, M.R., Burd, C.G., Emr, S.D. Curr. Biol. (1999) [Pubmed]
  16. The phosphatidylinositol 3-phosphate binding protein Vac1p interacts with a Rab GTPase and a Sec1p homologue to facilitate vesicle-mediated vacuolar protein sorting. Tall, G.G., Hama, H., DeWald, D.B., Horazdovsky, B.F. Mol. Biol. Cell (1999) [Pubmed]
  17. Cytoplasm to vacuole trafficking of aminopeptidase I requires a t-SNARE-Sec1p complex composed of Tlg2p and Vps45p. Abeliovich, H., Darsow, T., Emr, S.D. EMBO J. (1999) [Pubmed]
  18. Sly1 protein bound to Golgi syntaxin Sed5p allows assembly and contributes to specificity of SNARE fusion complexes. Peng, R., Gallwitz, D. J. Cell Biol. (2002) [Pubmed]
  19. Interactions of the Trichoderma reesei rho3 with the secretory pathway in yeast and T. reesei. Vasara, T., Salusjärvi, L., Raudaskoski, M., Keränen, S., Penttilä, M., Saloheimo, M. Mol. Microbiol. (2001) [Pubmed]
  20. Mso1 is a novel component of the yeast exocytic SNARE complex. Castillo-Flores, A., Weinberger, A., Robinson, M., Gerst, J.E. J. Biol. Chem. (2005) [Pubmed]
  21. Prospore membrane formation defines a developmentally regulated branch of the secretory pathway in yeast. Neiman, A.M. J. Cell Biol. (1998) [Pubmed]
  22. The Sec1 family: a novel family of proteins involved in synaptic transmission and general secretion. Halachmi, N., Lev, Z. J. Neurochem. (1996) [Pubmed]
  23. Two new Ypt GTPases are required for exit from the yeast trans-Golgi compartment. Jedd, G., Mulholland, J., Segev, N. J. Cell Biol. (1997) [Pubmed]
  24. A novel RING finger protein, Vps8p, functionally interacts with the small GTPase, Vps21p, to facilitate soluble vacuolar protein localization. Horazdovsky, B.F., Cowles, C.R., Mustol, P., Holmes, M., Emr, S.D. J. Biol. Chem. (1996) [Pubmed]
  25. Multicopy suppressors of the sly1 temperature-sensitive mutation in the ER-Golgi vesicular transport in Saccharomyces cerevisiae. Kosodo, Y., Imai, K., Hirata, A., Noda, Y., Takatsuki, A., Adachi, H., Yoda, K. Yeast (2001) [Pubmed]
  26. Sec1p directly stimulates SNARE-mediated membrane fusion in vitro. Scott, B.L., Van Komen, J.S., Irshad, H., Liu, S., Wilson, K.A., McNew, J.A. J. Cell Biol. (2004) [Pubmed]
  27. Characterization of the sec1-1 and sec1-11 mutations. Brummer, M.H., Kivinen, K.J., Jäntti, J., Toikkanen, J., Söderlund, H., Keränen, S. Yeast (2001) [Pubmed]
  28. Increased expression of the SNARE accessory protein Munc18c in lipid-mediated insulin resistance. Schlaepfer, I.R., Pulawa, L.K., Ferreira, L.D., James, D.E., Capell, W.H., Eckel, R.H. J. Lipid Res. (2003) [Pubmed]
  29. Cytochemical evaluation of localization and secretion of a heterologous enzyme displayed on yeast cell surface. Shibasaki, Y., Kamasawa, N., Shibasaki, S., Zou, W., Murai, T., Ueda, M., Tanaka, A., Osumi, M. FEMS Microbiol. Lett. (2000) [Pubmed]
WikiGenes - Universities