Fig. 6: KHSRP is responsible for recruiting U2 snRNP to the BS regions.

The distribution of KHSRP CLIP peak centers in the intronic regions according to eCLIP data (GSE177285). A The binding regions of KHSRP are enriched in introns, within which KHSRP preferentially binds at the regions close to the 5′ and 3′ splice sites, the latter of which is the typical location of the BS region. B Enriched peaks of KHSRP were observed at BS regions on introns 1 and 20 of EGFR and introns 3 and 14 of SF3B1 according to eCLIP data (GSE177285). NBS represents non-BS region on the introns. C Western blot analysis of SF3B1, EGFR, PHF5A, and CDC25A pulled down using biotinylated BS RNA probes in HL7702 cells. Antisense RNAs (AS), the non-BS region on the introns (NBS), blank beads, and BS mutated probes (Mut) were used as negative controls. D Associations of KHSRP or SF3B1 with RNAs containing BS regions were detected in KHSRP-knockdown cells using RIP. RNAs enriched with IgG were set as 1. The ARE regions in the TGF-β1 3′-UTR and U2 snRNA were used as positive controls. Data represent means ± SEM from three independent experiments. *p < 0.05.