Cleavage And Polyadenylation Specific Factor 2 (CPSF2)

A poly(A) tail is added to eukaryotic mRNA precursors after tightly coupled cleavage and polyadenylation reactions at their 3-prime ends. The factor responsible for this activity, CPSF, contains multiple subunits.Northern blot analysis using bovine Cpsf2 coding sequences revealed expression of 5.6-, 4.6-, 3.8-, and 3.0-kb transcripts in HeLa cells. Immunoblot analysis showed expression of a 100-kD nuclear protein in bovine and human cells. Immunofluorescence microscopy demonstrated expression of both the 100-kD and the 160-kD (CPSF1) CPSF subunits in nucleoplasm but not in nucleoli.The partial human protein is 99% identical to the 782-amino acid bovine protein. RT-PCR analysis revealed ubiquitous but variable expression of CPSF2, with highest levels in liver and testis.