The RNA-binding protein PTBP3 regulates alternative polyadenylation in naïve B cells

PTBP1 and PTBP2 have been extensively characterized as important splicing factors regulating many biological processes. PTBP3 is reported to be essential for AID-targeting specificity in activated B cells.

However, the physiological roles and regulatory mechanisms of PTBP3 in naive B cells are largely unknown. Here, we identified PTBP3 as a regulator of alternative polyadenylation using 2P-seq data in naive B cells. We revealed that PTBP3 promoted poly(A) signal recognition through binding to CU-rich elements in 3’ UTR and interacting with CPSF6 factor in a position- and dosage-dependent manner.