Helicase; has ATPase activity. Component of the SKI complex which is thought to be involved in exosome-mediated RNA decay and associates with transcriptionally active genes in a manner dependent on PAF1 complex (PAF1C). (updated: March 4, 2015)
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
No sequence conservation computed yet.
Total structural coverage: 92%
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The reference OMIM entry for this protein is 600478
Superkiller viralicidic activity 2, s. cerevisiae, homolog-like; skiv2l
Ski2, s. cerevisiae, homolog of; ski2
Ski2w
CLONING
Lee et al. (1995) identified a human cDNA with sequence homology to the yeast nucleolar protein gene SKI2. SKI2 belongs to a group of 6 yeast genes that repress the copy number of single- and double-stranded RNA viruses. Lee et al. (1995) identified the cDNA by immunoscreening an expression library with a monoclonal antibody raised against bovine pigmented retinal cells. The antibody recognizes a 90-kD nuclear antigen in a number of species. Helicases are involved in DNA replication, DNA repair, recombination, transcription, RNA splicing, and translation. Dangel et al. (1995) cloned a putative human helicase, which they designated SKI2W, that is located between the RD gene (
154040) and a gene they called RP1 (D6S60E; see Shen et al., 1994) in the class III region of the major histocompatibility complex on chromosome 6. The gene occurs within an approximately 11-kb span between RD and RP1. The cDNA was isolated from a set of lymphocyte libraries and the predicted 1,246-amino acid protein (137 kD) contains motifs associated with RNA helicases and has a leucine zipper domain. The protein shares extensive similarity (39% identity) to the yeast Ski2p gene which is involved in the inhibition of translation of non-polyadenylated RNA and has an important role in defense against infection by single- and double-stranded RNA viruses. The authors showed that the recombinant SKI2W protein exhibits ATPase activity. Northern blots indicated a 3.9-kb transcript in a variety of human transformed lines. Dangel et al. (1995) stated that this gene was very similar in sequence to that reported by Lee et al. (1995) and that discrepancies between the 2 sequences were probably the result of cloning artifacts. Inherently unstable mammalian mRNAs contain AU-rich elements (AREs) within their 3-prime untranslated regions. In yeast, 3-prime-to-5-prime mRNA degradation is mediated by the exosome, a multisubunit particle. Chen et al. (2001) purified and characterized the human exosome by mass spectrometry and found its composition to be similar to its yeast counterpart. They identified the following protein subunits within the human exosome: p7, which is homologous to the yeast Rrp4 protein (
602238); p8, which is homologous to the yeast Rrp42 protein (
606488); p9, which is homologous to the yeast Rrp43 protein (OIP2;
606019); p10, which is homologous to the yeast Rrp40 protein (
606489); p11, which is homologous to the yeast Mtr3 protein (
606490); p12A, which is homologous to the yeast Rrp41 protein (
606491); p12B, which is homologous to the yeast Rrp46 protein (
606492); and p13, which is homologous to the yeast Csl4 protein (
606493). They also identified 2 exosome-associated factors, p1 (SKIV2L) and p14 (MPP6;
605500), that were not homologous to any yeast exosome components.
GENE STRUCTURE
By genomic sequence analysis, Yang et al. (1998) determined that SKIV2L is a polymorphic gene that spans 11 kb and contains 28 exons.
MAPPING
Lee et al. (1995) isolated genomic clones and mapped the human homolog of SKI2 gene to 6p21 by fluorescence in situ hybridization. By genomic sequence analysis, Yang et al. (1998) determined that the SKIV2L gene is located 171 bp downstream from the RD gene.
GENE FUNCTION
Using a cell-free RNA decay system, Chen et al. (2001) demonstrated that the mammalian exosome is required for rapid degradation of ARE-containing RNAs but not for poly(A) shortening. They found that the mammalian exosome ...
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Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated
June 20, 2017: Protein entry updated
Automatic update: comparative model was added.
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 600478 was added.