Cleavage and polyadenylation specificity factor (CPSF) is a multisubunit complex that plays a central role in 3-prime processing of pre-mRNAs. CPSF recognizes the AAUAAA signal in the pre-mRNA and interacts with other proteins to facilitate both RNA cleavage and poly(A) synthesis. CPSF1 is the largest subunit of the CPSF complex (Murthy and Manley, 1995 [PubMed 7590244]).[supplied by OMIM, Mar 2008].