Splicing factor 3B subunit 3 (SF3B3)

Splicing factor 3B subunit 3 (SF3B3) is a core component of the SF3b protein complex, which together with SF3a and U2 small nuclear RNA forms the U2 small nuclear ribonucleoprotein (snRNP) complex. SF3B3 plays essential roles in recognizing branch point sequences during pre-mRNA splicing, anchoring U2 snRNP to pre-mRNA, and facilitating spliceosome assembly and activation. It also participates in the minor U12-type spliceosome, and is a subunit of chromatin-modifying complexes like STAGA and TFTC, linking it to transcription regulation and DNA repair. Dysregulation or mutation of SF3B3 is implicated in cancer and inherited syndromes, and it is a direct target for small-molecule splicing modulators such as E7107

Other names

SF3B3SAP130SF3b130RSE1STAF130KIAA0017Spliceosome-associated protein 130Pre-mRNA-splicing factor SF3b 130 kDa subunit

Competitive inhibition of branch point sequence binding in the spliceosome by occupying the BPA-binding pocket (e.g., E7107 modulates splicing by binding SF3b complex, disrupting pre-mRNA substrate recognition)