SF3B3
SF3B3 (splicing factor 3b subunit 3, also known as SAP130, SF3b130, RSE1 and KIAA0017) is a nuclear component of the SF3B subcomplex of the U2 snRNP. It helps the spliceosome recognise the intron branch site during pre-mRNA splicing. Browse Assay Genie's current range of SF3B3 research reagents below, or read on for the biology behind the target.
SF3B3 is a component of the 17S U2 snRNP complex of the spliceosome, the large ribonucleoprotein complex that removes introns from transcribed pre-mRNAs. The 17S U2 snRNP takes part directly in early spliceosome assembly and mediates recognition of the intron branch site by promoting selection of the branch-site adenosine, the nucleophile for the first step of splicing. Within this complex, SF3B3 sits in the SF3B subcomplex, which is required for formation of the 'A' complex, produced when U2 snRNP binds stably to the branchpoint sequence in pre-mRNA. SF3B3 may also be involved in assembly of the 'E' complex.
Splicing factor 3b, together with splicing factor 3a and a 12S RNA unit, forms the U2 snRNP. The SF3b/SF3a assembly binds pre-mRNA upstream of the branch site in a sequence-independent manner and may anchor the U2 snRNP to the transcript. SF3B3 also acts as a component of the minor spliceosome, which splices U12-type introns. The protein is localised to the nucleus and belongs to the RSE1 family. The SF3B3 gene is assigned by HGNC to the SF3b complex gene group, and the mouse ortholog is Sf3b3.
Beyond splicing, the NCBI Gene summary notes that SF3B3 has been identified in the STAGA (SPT3-TAF(II)31-GCN5L acetylase) transcription coactivator-HAT complex and in the TFTC (TATA-binding-protein-free TAF(II)-containing complex). These complexes may function in chromatin modification, transcription, splicing and DNA repair. The protein has also been catalogued as splicing factor 3b, subunit 3, 130kD, which explains the aliases SAP130 and SF3b130. Researchers studying the SF3B3 gene or SF3B3 protein therefore often work at the interface of RNA processing and chromatin regulation.
SF3B3 participates in early spliceosome assembly and in formation of the 'A' complex, making it relevant to the mechanics of U2 snRNP recruitment.
As part of the 17S U2 snRNP, SF3B3 supports selection of the branch-site adenosine that acts as nucleophile in the first splicing step.
SF3B3 is a component of the minor spliceosome, which handles splicing of U12-type introns in pre-mRNAs.
SF3B3 is found in the STAGA and TFTC complexes, which may function in chromatin modification, transcription, splicing and DNA repair.
SF3B3 is a subunit of the SF3B subcomplex within the 17S U2 snRNP. It contributes to early spliceosome assembly, branch-site recognition and 'A' complex formation during pre-mRNA splicing, and it also functions in the minor spliceosome that splices U12-type introns.
SF3B3 is also called SAP130, SF3b130, RSE1 and KIAA0017. Earlier HGNC names were splicing factor 3b, subunit 3, 130kD, and the 130kDa variant. The UniProt entry is named Splicing factor 3B subunit 3 and places it in the RSE1 family.
A mouse ortholog, Sf3b3, is recorded for the human gene. The RSE1 family name reflects relatives defined in other organisms. Check the datasheet of any product for its validated reactivity before using it in a given species.
Other splicing factors and SF3b complex relatives with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q15393; product specifications from Assay Genie datasheets.