SNF8/YPL002C Summary Help

Standard Name SNF8 1
Systematic Name YPL002C
Alias VPS22 2 , 3 , VPL14 3
Feature Type ORF, Verified
Description Component of the ESCRT-II complex; ESCRT-II is involved in ubiquitin-dependent sorting of proteins into the endosome; appears to be functionally related to SNF7; involved in glucose derepression (4 and see Summary Paragraph)
Name Description Sucrose NonFermenting 1, 5
Chromosomal Location
ChrXVI:554328 to 553627 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gbrowse
Gene Ontology Annotations All SNF8 GO evidence and references
  View Computational GO annotations for SNF8
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 1 genes
Resources
Classical genetics
null
reduction of function
Large-scale survey
null
overexpression
Resources
82 total interaction(s) for 55 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 10
  • Affinity Capture-RNA: 1
  • Affinity Capture-Western: 6
  • Co-crystal Structure: 3
  • Two-hybrid: 18

Genetic Interactions
  • Dosage Growth Defect: 1
  • Dosage Lethality: 1
  • Dosage Rescue: 1
  • Negative Genetic: 3
  • Phenotypic Enhancement: 3
  • Phenotypic Suppression: 2
  • Synthetic Growth Defect: 18
  • Synthetic Haploinsufficiency: 1
  • Synthetic Lethality: 13
  • Synthetic Rescue: 1

Resources
Expression Summary
histogram
Resources
Length (a.a.) 233
Molecular Weight (Da) 26,954
Isoelectric Point (pI) 5.51
Localization
Phosphorylation PhosphoGRID | PhosphoPep Database
Structure
Homologs
sequence information
ChrXVI:554328 to 553627 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
SGD ORF map
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Relative
Coordinates
Chromosomal
Coordinates
Most Recent Updates
Coordinates Sequence
CDS 1..702 554328..553627 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
Resources
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000005923
SUMMARY PARAGRAPH for SNF8

Most proteins targeted for degradation in the multivesicular body (MVB) pathway are monoubiquitinated, then passed through the ESCRT complexes (Endosomal Sorting Complex Required for Transport), a series of highly-conserved multisubunit complexes. ESCRT I, II, and III are sequentially mobilized to endosomal membranes, where they direct protein sorting and MVB biogenesis, and play a crucial role in retrovirus budding (6).

ESCRT II (composed of Snf8p, Vps25p, and Vps36p) is a 155-kDa trilobal cytoplasmic complex that transiently associates with endosomes and appears to regulate the formation of ESCRT III (Did4p, Snf7p, Vps20p and Vps24p) (7). The ESCRT II core, which contains two copies of Vps25p, one copy of Snf8p, and the C-terminal region of Vps36p, consists of eight repeats of a common building block, a "winged helix" domain. Two PPXY-motifs from Vps25p are involved in contacts with Snf8p and Vps36p, and their mutation leads to disruption of the complex (6). Each ESCRT II subunit binds the other two subunits of ESCRT II, as well as Vps28p of ESCRT I and Vps20p of ESCRT III, with Vps25p being the main subunit responsible for the interaction with Vps20p (8, 6). Vps36p also binds ubiquitinated target proteins (4).

Null mutants in SNF8, VPS25, or VPS36 are extremely sensitive to calcium, lithium or manganese ions, and to high temperatures (9). These mutants also display mislocalization of Rim20p to a few large perivacuolar foci, suggesting that ESCRT II is involved in regulating Rim20p localization (10). snf8, vps20 or vps36 nulls also accumulate Fur4p at the plasma membrane, which increases uptake of 5-fluorouracil (5-FU), a toxic analog of uracil (11).

The human homologs of the ESCRT II proteins interact with one another, with human Vps20p (a component of ESCRT III) and with their yeast homologs. siRNA depletion of mammalian ESCRT II does not affect degradation of epidermal growth factor, a known cargo of the multivesicular body protein sorting pathway, suggesting that mammalian ESCRT II may be redundant, cargo-specific, or not required for protein sorting at the multivesicular body (12, 13, 14).

SNF8 was isolated in a search for vacuolar protein sorting (vps) mutants, and also in a search for mutants defective for growth on medium containing raffinose plus antimycin A. snf8 null mutants are defective in derepressing the transcription of SUC2, and display a growth defect on raffinose, slow growth on sucrose, a slight growth defect on glycerol, and normal growth on galactose. Diploid homozygous null mutants are defective in sporulation (1, 15).

SNF8 is similar to Caenorhabditis elegans predicted protein C27F2.5, to a region containing a modifying locus for murine plasma von Willebrand factor level (16), and to human SNF8 and rat RGD1310144, which are subunits of the ELL complex (17, 12).`

Last updated: 2006-02-07 Contact SGD

References cited on this page View Complete Literature Guide for SNF8
1) Vallier LG and Carlson M  (1991) New SNF genes, GAL11 and GRR1 affect SUC2 expression in Saccharomyces cerevisiae. Genetics 129(3):675-84
2) Robinson JS, et al.  (1988) Protein sorting in Saccharomyces cerevisiae: isolation of mutants defective in the delivery and processing of multiple vacuolar hydrolases. Mol Cell Biol 8(11):4936-48
3) Rothman JH, et al.  (1989) Characterization of genes required for protein sorting and vacuolar function in the yeast Saccharomyces cerevisiae. EMBO J 8(7):2057-65
4) Hierro A, et al.  (2004) Structure of the ESCRT-II endosomal trafficking complex. Nature 431(7005):221-5
5) Carlson M, et al.  (1981) Mutants of yeast defective in sucrose utilization. Genetics 98(1):25-40
6) Teo H, et al.  (2004) ESCRT-II, an endosome-associated complex required for protein sorting: crystal structure and interactions with ESCRT-III and membranes. Dev Cell 7(4):559-69
7) Babst M, et al.  (2002) Endosome-associated complex, ESCRT-II, recruits transport machinery for protein sorting at the multivesicular body. Dev Cell 3(2):283-9
8) Bowers K and Stevens TH  (2005) Protein transport from the late Golgi to the vacuole in the yeast Saccharomyces cerevisiae. Biochim Biophys Acta 1744(3):438-54
9) Eguez L, et al.  (2004) Yeast Mn2+ transporter, Smf1p, is regulated by ubiquitin-dependent vacuolar protein sorting. Genetics 167(1):107-17
10) Boysen JH and Mitchell AP  (2006) Control of Bro1-domain protein Rim20 localization by external pH, ESCRT machinery, and the Saccharomyces cerevisiae Rim101 pathway. Mol Biol Cell 17(3):1344-53
11) Bugnicourt A, et al.  (2004) Antagonistic roles of ESCRT and Vps class C/HOPS complexes in the recycling of yeast membrane proteins. Mol Biol Cell 15(9):4203-14
12) Kamura T, et al.  (2001) Cloning and characterization of ELL-associated proteins EAP45 and EAP20. a role for yeast EAP-like proteins in regulation of gene expression by glucose. J Biol Chem 276(19):16528-33
13) Raiborg C, et al.  (2003) Protein sorting into multivesicular endosomes. Curr Opin Cell Biol 15(4):446-55
14) Bowers K, et al.  (2006) Degradation of endocytosed epidermal growth factor and virally ubiquitinated major histocompatibility complex class I is independent of mammalian ESCRTII. J Biol Chem 281(8):5094-105
15) Yeghiayan P, et al.  (1995) Molecular analysis of the SNF8 gene of Saccharomyces cerevisiae. Yeast 11(3):219-24
16) Mohlke KL, et al.  (1998) Comparative mapping of distal murine chromosome 11 and human 17q21.3 in a region containing a modifying locus for murine plasma von Willebrand factor level. Genomics 54(1):19-30
17) Schmidt AE, et al.  (1999) Cloning and characterization of the EAP30 subunit of the ELL complex that confers derepression of transcription by RNA polymerase II. J Biol Chem 274(31):21981-5