SF3A1
Description
The SF3A1 (splicing factor 3a subunit 1) is a protein-coding gene located on chromosome 22.
Splicing factor 3 subunit 1 is a protein that in humans is encoded by the SF3A1 gene. This gene encodes subunit 1 of the splicing factor 3a protein complex. The splicing factor 3a heterotrimer includes subunits 1, 2 and 3 and is necessary for the in vitro conversion of 15S U2 snRNP into an active 17S particle that performs pre-mRNA splicing. Subunit 1 belongs to the SURP protein family; named for the SURP (also called SWAP or Suppressor-of-White-APricot) motifs that are thought to mediate RNA binding. Subunit 1 has tandemly repeated SURP motifs in its amino-terminal half while its carboxy-terminal half contains a proline-rich region and a ubiquitin-like domain. Binding studies with truncated subunit 1 derivatives demonstrated that the two SURP motifs are necessary for binding to subunit 3 while contacts with subunit 2 may occur through sequences carboxy-terminal to the SURP motifs. Alternative splicing results in multiple transcript variants encoding different isoforms. SF3A1 has been shown to interact with SF3A3 and CDC5L.
SF3A1 is a component of the 17S U2 snRNP complex, a large ribonucleoprotein complex involved in removing introns from transcribed pre-mRNAs. The 17S U2 snRNP complex plays a crucial role in early spliceosome assembly and mediates recognition of the intron branch site during pre-mRNA splicing. SF3A1 is part of the SF3A subcomplex, which contributes to the assembly of the 17S U2 snRNP, and subsequently, the assembly of the pre-spliceosome 'E' complex and the pre-catalytic spliceosome 'A' complex. SF3A1 also participates in pre-mRNA splicing as a component of pre-catalytic spliceosome 'B' complexes.
SF3A1 is also known as PRP21, PRPF21, SAP114, SF3A120.
