RC74: Proteins and Enzymes

Formation of the mature 3' ends of the vast majority of cellular mRNAs occurs through cleavage and polyadenylation and requires a cleavage and polyadenylation specificity factor (CPSF) containing, among other proteins, CPSF-73 and CPSF-100. RC-74 is an exclusively nuclear protein found in HeLa cells that has similar characteristics to CPSF-100. Like the complex that forms between CPSF-100 and CPSF-73, studies show that RC-74 may form a similar complex with RC-68 that is independent from the CPSF complex. This RC-68 / RC-74 complex may be involved in a pre-mRNA processing event other than cleavage and polyadenylation, such as the 3' end processing of a distinct subset of cellular pre-mRNAs encoding proteins required for G(1) progression and entry into S phase.