SKI2/YLR398C Summary Help

Standard Name SKI2 1
Systematic Name YLR398C
Feature Type ORF, Verified
Description Ski complex component and putative RNA helicase; mediates 3'-5' RNA degradation by the cytoplasmic exosome; null mutants have superkiller phenotype of increased viral dsRNAs and are synthetic lethal with mutations in 5'-3' mRNA decay; mutations in the human ortholog, SKIV2L, causes Syndromic diarrhea/Trichohepatoenteric (SD/THE) syndrome (1, 2, 3, 4, 5 and see Summary Paragraph)
Name Description SuperKIller 1
Chromosomal Location
ChrXII:919019 to 915156 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All SKI2 GO evidence and references
  View Computational GO annotations for SKI2
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 1 genes
Classical genetics
Large-scale survey
198 total interaction(s) for 130 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 41
  • Affinity Capture-RNA: 2
  • Affinity Capture-Western: 5
  • Co-purification: 1
  • Reconstituted Complex: 2
  • Two-hybrid: 2

Genetic Interactions
  • Dosage Growth Defect: 3
  • Dosage Lethality: 1
  • Negative Genetic: 64
  • Phenotypic Enhancement: 5
  • Phenotypic Suppression: 12
  • Positive Genetic: 36
  • Synthetic Growth Defect: 11
  • Synthetic Lethality: 7
  • Synthetic Rescue: 6

Expression Summary
Length (a.a.) 1,287
Molecular Weight (Da) 146,057
Isoelectric Point (pI) 6.72
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXII:919019 to 915156 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2004-02-05 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..3864 919019..915156 2004-02-05 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000004390

The SKI complex is a cytoplasmic complex composed of a putative RNA helicase (Ski2p), a tetratricopeptide repeat protein (Ski3p) and a WD repeat protein (Ski8p) (2 and references therein). Along with the adaptor protein Ski7p, the SKI complex mediates the cytoplasmic functions of the exosome, a 3'-5' exonuclease complex (6, 7). Together, the SKI complex, Ski7p and the exosome function in a wide range of 3'-5' RNA catabolic processes that include the routine turnover of normal mRNAs (4), the degradation of aberrant mRNAs by 3'-5' nonsense-mediated decay (8) and non-stop mRNA decay (9), and the degradation of other cytoplasmic RNAs including unadenylated RNAs (10) and viral dsRNA (1, 11). Although the SKI complex was originally described as a heterotrimer containing Ski2p, Ski3p and Ski8p (2, 12), later work provides evidence that it is a heterotetramer containing one subunit each of Ski2p and Ski3p, and two subunits of Ski8p (13).

All members of the SKI complex are found in humans and the human genes for hSKI2 (SKIV2L) and hSKI8 (WDR61) have been identified (14, 15, 16). However, Ski7p is found only in a subset of Saccharomyces species (17); the closely related protein, Hbs1p, is likely to fill the role of Ski7p in other fungi and possibly other eukaryotes (18).

Null mutants of ski2, ski3, ski8 and ski7 have similar phenotypes. All have the superkiller phenotype indicative of increased accumulation or viral dsRNA (19 and references therein), and exhibit synthetic lethality with mutations in genes involved in 5'-3' mRNA decay (4, 6).

Last updated: 2009-03-24 Contact SGD

References cited on this page View Complete Literature Guide for SKI2
1) Toh-E A, et al.  (1978) Chromosomal superkiller mutants of Saccharomyces cerevisiae. J Bacteriol 136(3):1002-7
2) Brown JT, et al.  (2000) The yeast antiviral proteins Ski2p, Ski3p, and Ski8p exist as a complex in vivo. RNA 6(3):449-57
3) Widner WR and Wickner RB  (1993) Evidence that the SKI antiviral system of Saccharomyces cerevisiae acts by blocking expression of viral mRNA. Mol Cell Biol 13(7):4331-41
4) Jacobs JS, et al.  (1998) The 3' to 5' degradation of yeast mRNAs is a general mechanism for mRNA turnover that requires the SKI2 DEVH box protein and 3' to 5' exonucleases of the exosome complex. EMBO J 17(5):1497-506
5) Fabre A, et al.  (2012) SKIV2L mutations cause syndromic diarrhea, or trichohepatoenteric syndrome. Am J Hum Genet 90(4):689-92
6) van Hoof A, et al.  (2000) Function of the ski4p (Csl4p) and Ski7p proteins in 3'-to-5' degradation of mRNA. Mol Cell Biol 20(21):8230-43
7) Araki Y, et al.  (2001) Ski7p G protein interacts with the exosome and the Ski complex for 3'-to-5' mRNA decay in yeast. EMBO J 20(17):4684-93
8) Mitchell P and Tollervey D  (2003) An NMD pathway in yeast involving accelerated deadenylation and exosome-mediated 3'-->5' degradation. Mol Cell 11(5):1405-13
9) van Hoof A, et al.  (2002) Exosome-mediated recognition and degradation of mRNAs lacking a termination codon. Science 295(5563):2262-4
10) Brown JT and Johnson AW  (2001) A cis-acting element known to block 3' mRNA degradation enhances expression of polyA-minus mRNA in wild-type yeast cells and phenocopies a ski mutant. RNA 7(11):1566-77
11) Ridley SP, et al.  (1984) Superkiller mutations in Saccharomyces cerevisiae suppress exclusion of M2 double-stranded RNA by L-A-HN and confer cold sensitivity in the presence of M and L-A-HN. Mol Cell Biol 4(4):761-70
12) Wang L, et al.  (2005) Domain interactions within the Ski2/3/8 complex and between the Ski complex and Ski7p. RNA 11(8):1291-302
13) Synowsky SA and Heck AJ  (2008) The yeast Ski complex is a hetero-tetramer. Protein Sci 17(1):119-25
14) Lee SG, et al.  (1995) Identification and characterization of a human cDNA homologous to yeast SKI2. Genomics 25(3):660-6
15) Dangel AW, et al.  (1995) Human helicase gene SKI2W in the HLA class III region exhibits striking structural similarities to the yeast antiviral gene SKI2 and to the human gene KIAA0052: emergence of a new gene family. Nucleic Acids Res 23(12):2120-6
16) Zhu B, et al.  (2005) The human PAF complex coordinates transcription with events downstream of RNA synthesis. Genes Dev 19(14):1668-73
17) Atkinson GC, et al.  (2008) Evolution of nonstop, no-go and nonsense-mediated mRNA decay and their termination factor-derived components. BMC Evol Biol 8:290
18) van Hoof A  (2005) Conserved functions of yeast genes support the duplication, degeneration and complementation model for gene duplication. Genetics 171(4):1455-61
19) Wickner RB  (1996) Double-stranded RNA viruses of Saccharomyces cerevisiae. Microbiol Rev 60(1):250-65