Alternative titles; symbols
HGNC Approved Gene Symbol: SRSF7
Cytogenetic location: 2p22.1 Genomic coordinates (GRCh38): 2:38,743,599-38,751,494 (from NCBI)
Cavaloc et al. (1994) used a monoclonal antibody to identify a splicing factor of 35 kD which they named 9G8. Based on partial sequence of tryptic peptides, the authors designed degenerate PCR primers and obtained a PCR product which was used to probe genomic and cDNA libraries. The isolation and characterization of cDNA clones indicated that the 9G8 protein (gene symbol, SFRS7) is a member of the serine/arginine (SR) splicing factor family because it includes an N-terminal RNA binding domain and a C-terminal SR domain. Members of this family are thought to play key roles in alternative splicing. The RNA binding domain of 9G8 is closely related (79 to 71% identity) to those of the SR factors human SRp20 (603364) and Drosophila RBP1. Immunodepletion of the 9G8 protein from a nuclear extract resulted in the loss of splicing activity. In turn, in vitro-expressed recombinant 9G8 protein rescued the splicing activity of a 9G8-depleted nuclear extract.
Popielarz et al. (1995) isolated and characterized the human 9G8 gene. The gene spans 7,745 bp and consists of 8 exons and 7 introns within the coding sequence, thus contrasting with the organization of some other genes of the SR splicing factor family. The 5-prime flanking region is GC-rich and contains basal promoter sequences and potential regulatory elements. They presented results raising the possibility that alternative splicing of intron 3 provides a mechanism for modulation of the 9G8 function.
Lareau et al. (2007) reported that in every member of the human SR family of splicing regulators, highly or ultraconserved elements are alternatively spliced, either as alternative 'poison cassette exons' containing early in-frame stop codons, or as alternative introns in the 3-prime untranslated region. These alternative splicing events target the resulting mRNAs for degradation by means of an RNA surveillance pathway called nonsense-mediated mRNA decay. Mouse orthologs of the human SR proteins exhibit the same unproductive splicing patterns. Three SR proteins, SRp20 (603364), SC35 (600813), and 9G8 (SFRS7), had been previously shown to direct splicing of their own transcripts, and SC35 autoregulates its expression by coupling alternative splicing with decay. Lareau et al. (2007) concluded that unproductive splicing is important for regulation of the entire SR family and found that unproductive splicing associated with conserved regions has arisen independently in different SR genes, suggesting that splicing factors may readily acquire this form of regulation.
By isotopic in situ hybridization, Popielarz et al. (1995) localized the SFRS7 gene to 2p22-p21.
Cavaloc, Y., Popielarz, M., Fuchs, J.-P., Gattoni, R., Stevenin, J. Characterization and cloning of the human splicing factor 9G8: a novel 35 kDa factor of the serine/arginine protein family. EMBO J. 13: 2639-2649, 1994. [PubMed: 8013463] [Full Text: https://doi.org/10.1002/j.1460-2075.1994.tb06554.x]
Lareau, L. F., Inada, M., Green, R. E., Wengrod, J. C., Brenner, S. E. Unproductive splicing of SR genes associated with highly conserved and ultraconserved DNA elements. Nature 446: 926-929, 2007. [PubMed: 17361132] [Full Text: https://doi.org/10.1038/nature05676]
Popielarz, M., Cavaloc, Y., Mattei, M.-G., Gattoni, R., Stevenin, J. The gene encoding human splicing factor 9G8: structure, chromosomal localization, and expression of alternatively processed transcripts. J. Biol. Chem. 270: 17830-17835, 1995. [PubMed: 7629084] [Full Text: https://doi.org/10.1074/jbc.270.30.17830]