SEC18/YBR080C Summary Help

Standard Name SEC18 1, 2, 3
Systematic Name YBR080C
Alias ANU4
Feature Type ORF, Verified
Description AAA ATPase and SNARE disassembly chaperone; required for vesicular transport between ER and Golgi, the 'priming' step in homotypic vacuole fusion, autophagy, and protein secretion; releases Sec17p from SNAP complexes; has similarity to mammalian N-ethylmaleimide-sensitive factor (NSF) (1, 4, 5, 6, 7 and see Summary Paragraph)
Name Description SECretory 8
Chromosomal Location
ChrII:400890 to 398614 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Genetic position: 48 cM
Gene Ontology Annotations All SEC18 GO evidence and references
  View Computational GO annotations for SEC18
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 4 genes
Classical genetics
Large-scale survey
reduction of function
163 total interaction(s) for 129 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 25
  • Affinity Capture-RNA: 2
  • Affinity Capture-Western: 24
  • Co-fractionation: 3
  • PCA: 2
  • Reconstituted Complex: 4
  • Two-hybrid: 8

Genetic Interactions
  • Dosage Growth Defect: 2
  • Dosage Lethality: 2
  • Dosage Rescue: 4
  • Negative Genetic: 53
  • Phenotypic Enhancement: 3
  • Phenotypic Suppression: 3
  • Positive Genetic: 6
  • Synthetic Growth Defect: 9
  • Synthetic Lethality: 13

Expression Summary
Length (a.a.) 758
Molecular Weight (Da) 84,055
Isoelectric Point (pI) 8.08
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrII:400890 to 398614 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Genetic position: 48 cM
Last Update Coordinates: 2011-02-03 | Sequence: 1997-01-28
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..2277 400890..398614 2011-02-03 1997-01-28
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000000284

SEC17 and SEC18 act as SNARE chaperones during protein transport between organelles (such as ER to Golgi transport), transport to and from the plasma membrane (such as protein secretion), and fusion between organelles (such as homotypic vacuole fusion) (9, 10). Sec18p is an AAA-ATPase whose activity is stimulated by Sec17p (11). Sec18p is the yeast homolog of the mammalian NSF and Sec17p is the yeast homolog of the mammalian alpha-SNAP (4, 12).

During ER to Golgi transport, Sec17p and Sec18p bind SNARE complexes that formed after the ER-derived vesicle has docked with the Golgi membrane and are required for membrane fusion (13, 14, 15). In contrast, during homotypic vacuole fusion, Sec17p and Sec18p are required prior to docking and membrane fusion (7). Sec17p and Sec18p bind SNARE complexes that have accumulated on vacuole membranes from previous fusion events. Then the ATPase activity of Sec18p drives disassembly of these SNARE complexes and primes them for another round of vacuolar fusion (6). Based on Sec17p and Sec18p function during yeast homotypic vacuole fusion as well as studies in mammalian systems of other membrane fusion events, Sec17p and Sec18p are proposed to facilitate the recycling of SNARE proteins during all membrane fusion events (16).

Last updated: 2010-05-12 Contact SGD

References cited on this page View Complete Literature Guide for SEC18
1) Eakle KA, et al.  (1988) Characterization of a component of the yeast secretion machinery: identification of the SEC18 gene product. Mol Cell Biol 8(10):4098-109
2) Novick P, et al.  (1980) Identification of 23 complementation groups required for post-translational events in the yeast secretory pathway. Cell 21(1):205-15
3) Fields, C. and Schekman, R.  (1985) Personal Communication, Mortimer Map Edition 9
4) Wilson DW, et al.  (1989) A fusion protein required for vesicle-mediated transport in both mammalian cells and yeast. Nature 339(6223):355-9
5) Newman AP and Ferro-Novick S  (1990) Defining components required for transport from the ER to the Golgi complex in yeast. Bioessays 12(10):485-91
6) Mayer A, et al.  (1996) Sec18p (NSF)-driven release of Sec17p (alpha-SNAP) can precede docking and fusion of yeast vacuoles. Cell 85(1):83-94
7) Ungermann C, et al.  (1998) A vacuolar v-t-SNARE complex, the predominant form in vivo and on isolated vacuoles, is disassembled and activated for docking and fusion. J Cell Biol 140(1):61-9
8) Novick P and Schekman R  (1979) Secretion and cell-surface growth are blocked in a temperature-sensitive mutant of Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 76(4):1858-62
9) Bonifacino JS and Glick BS  (2004) The mechanisms of vesicle budding and fusion. Cell 116(2):153-66
10) Ostrowicz CW, et al.  (2008) Yeast vacuole fusion: a model system for eukaryotic endomembrane dynamics. Autophagy 4(1):5-19
11) Steel GJ, et al.  (1999) Biochemical analysis of the Saccharomyces cerevisiae SEC18 gene product: implications for the molecular mechanism of membrane fusion. Biochemistry 38(24):7764-72
12) Griff IC, et al.  (1992) The yeast SEC17 gene product is functionally equivalent to mammalian alpha-SNAP protein. J Biol Chem 267(17):12106-15
13) Sogaard M, et al.  (1994) A rab protein is required for the assembly of SNARE complexes in the docking of transport vesicles. Cell 78(6):937-48
14) Barlowe C  (1997) Coupled ER to Golgi transport reconstituted with purified cytosolic proteins. J Cell Biol 139(5):1097-108
15) Muniz M, et al.  (2001) Protein sorting upon exit from the endoplasmic reticulum. Cell 104(2):313-20
16) Hong W  (2005) SNAREs and traffic. Biochim Biophys Acta 1744(2):120-44