Alternative titles; symbols
HGNC Approved Gene Symbol: SCAF11
Cytogenetic location: 12q12 Genomic coordinates (GRCh38) : 12:45,919,131-45,992,059 (from NCBI)
Like other SR proteins, the SC35 (600813) splicing factor contains an arginine/serine-rich (RS) domain and an RNA-binding motif. Using a yeast 2-hybrid screen with SC35 as bait, Zhang and Wu (1998) isolated a HeLa cell partial cDNA encoding SIP1, a novel SC35-interacting protein. They used the partial cDNA to screen a HeLa cell library and recovered cDNAs corresponding to the entire SIP1 coding region. The predicted 1,403-amino acid protein contains an RS domain similar to those found in several SR proteins and a region of weak similarity to the Drosophila splicing regulator suppressor of white-apricot (SWAP; 601945). In addition, the C-terminal region of SIP1 contains an RNA polymerase II C-terminal domain (CTD)-binding motif. Although the predicted molecular mass of SIP1 is 158 kD, the protein migrates at 210 kD by SDS-PAGE. The authors suggested that this discrepancy might result from posttranslational modifications such as phosphorylation, which is known to cause aberrant migration of several RS domain-containing proteins in SDS-PAGE.
By performing a yeast 2-hybrid assay to identify proteins that interact with CTD, Tanner et al. (1997) isolated partial cDNAs encoding SIP1, which they called CTD-associated SR protein 11 (CASP11) or SR-related protein of 129 kD (SRrp129). Northern blot analysis detected expression of the approximately 6-kb SRrp129 mRNA in all tissues tested.
Using yeast 2-hybrid assays and immunoprecipitation studies, Zhang and Wu (1998) showed that SIP1 interacted with several SR proteins, as well as with U2AF65 (191318) and U1-70K (180740), proteins associated with the 3-prime and 5-prime splice sites, respectively. Antibodies against SIP1 depleted splicing activity from a HeLa cell nuclear extract. In the SIP1-depleted nuclear extracts, formation of prespliceosomal complexes A and B was deficient. Zhang and Wu (1998) concluded that SIP1 is a novel RS domain protein required for pre-mRNA splicing.
By inclusion within a mapped clone, Tanner et al. (1997) mapped the SRrp129 gene to chromosome 21q22.3. However, Gross (2011) mapped the SCAF11 gene to chromosome 12q12 based on an alignment of the SCAF11 sequence (GenBank BC141552) with the genomic sequence (GRCh37).
Gross, M. B. Personal Communication. Baltimore, Md. 2/25/2011.
Tanner, S., Stagljar, I., Georgiev, O., Schaffner, W., Bourquin, J.-P. A novel SR-related protein specifically interacts with the carboxy-terminal domain (CTD) of RNA polymerase II through a conserved interaction domain. Biol. Chem. 378: 565-571, 1997. [PubMed: 9224939] [Full Text: https://doi.org/10.1515/bchm.1997.378.6.565]
Zhang, W.-J., Wu, J. Y. Sip1, a novel RS domain-containing protein essential for pre-mRNA splicing. Molec. Cell. Biol. 18: 676-684, 1998. [PubMed: 9447963] [Full Text: https://doi.org/10.1128/MCB.18.2.676]