This gene encodes a nuclear protein with an RRM (RNA recognition motif) domain. The protein is a member of the cleavage stimulation factor (CSTF) complex that is involved in the 3' end cleavage and polyadenylation of pre-mRNAs. Specifically, this protein binds GU-rich elements within the 3'-untranslated region of mRNAs. [provided by RefSeq, Jul 2008].