Component of the cleavage and polyadenylation specificity factor (CPSF) complex that play a key role in pre-mRNA 3'-end formation, recognizing the AAUAAA signal sequence and interacting with poly(A) polymerase and other factors to bring about cleavage and poly(A) addition. Cpsf4 binds RNA polymers with a preference for poly(U) (By similarity). Component of the cleavage and polyadenylation specificity factor (CPSF) complex, composed of cpsf1, cpsf2, cpsf3, cpsf4 and fip1l1. Belongs to the CPSF4/YTH1 family.