Fig. 2

Mechanisms of SR proteins in human cancers. a Two models of SR protein function in splicing. U2AF-recruitment model: ESE-bound SR proteins interact with U2AF35 at the 3′SS to stabilize the binding of U2AF65 at the polypyrimidine tract and recruit U1 snRNP at the 5′SS to active splicing. Coactivator model: ESE-bound SR proteins interact with splicing coactivator SRm160/300 and communicate with U1 snRNP and U2 snRNP. b Model of SRSF3- and SRSF7-mediated regulation of APA by interacting with the APA component on PASs in an antagonistic manner. c Model of SR proteins recognizing NMD factor UPF1 downstream of the PTC to activate the NMD pathway, thus inducing protein degradation. d Example of SR protein function in translation. SRSF1 recruits mammalian target of rapamycin complex 1 (mTORC1) to mRNA to promote phosphorylation of 4E-BP, leading to release of eIF4E and initiation of translation. e SR proteins can interact with lncRNA, circRNA and microRNA to regulate tumorigenesis. f SR proteins can directly or indirectly interact with m⁶A methyltransferases, or colocalize with m⁶A readers to modulate m⁶A modification