SAP25

SAP25 (full name Spliceosome-associated protein 25), encoded by the SF3B5 gene, is a core subunit of the U2 small nuclear ribonucleoprotein (snRNP) complex. It stabilizes the interaction between U2 snRNP and the pre-mRNA branch point sequence, a key step in accurate pre-mRNA splicing. Common aliases include SF3B5 and p25.
Dysregulation of SAP25 contributes to splicing defects in cancers like leukemia and solid tumors, altering oncogene/tumor suppressor expression. As part of the SF3B spliceosome pathway, its mutations disrupt mRNA processing. Indirect inhibitors (e.g., pladienolide B) targeting the SF3B complex affect SAP25 function, showing early promise in cancer drug development.