Component of the cleavage factor Im (CFIm) complex that functions as an activator of the pre-mRNA 3'-end cleavage and polyadenylation processing required for the maturation of pre-mRNA into functional mRNAs (PubMed:17024186, PubMed:29276085, PubMed:8626397). CFIm contributes to the recruitment of multiprotein complexes on specific sequences on the pre-mRNA 3'-end, so called cleavage and polyadenylation signals (pA signals) (PubMed:17024186, PubMed:8626397). Most pre-mRNAs contain multiple pA signals, resulting in alternative cleavage and polyadenylation (APA) producing mRNAs with variable 3'-end formation (PubMed:23187700, PubMed:29276085). The CFIm complex acts as a key regulator of cleavage and polyadenylation site choice during APA through its binding to 5'-UGUA-3' elements localized in the 3'- untranslated region (UTR) for a huge number of pre-mRNAs (PubMed:20695905, PubMed:29276085). CPSF7 activates directly the mRNA 3'-processing machinery (PubMed:29276085). Binds to pA signals in RNA substrates (PubMed:17024186, PubMed:8626397). {ECO:0000269|PubMed:17024186, ECO:0000269|PubMed:20695905, ECO:0000269|PubMed:23187700, ECO:0000269|PubMed:29276085, ECO:0000269|PubMed:8626397}. This is the function of ENSG00000149532 (CPSF7, cleavage and polyadenylation specific factor 7).