CPSF3
Description
The CPSF3 (cleavage and polyadenylation specific factor 3) is a protein-coding gene located on chromosome 2.
Cleavage and polyadenylation specificity factor subunit 3 is a protein that in humans is encoded by the CPSF3 gene.
CPSF3 is a component of the cleavage and polyadenylation specificity factor (CPSF) complex, which plays a critical role in pre-mRNA 3'-end formation. It recognizes the AAUAAA signal sequence and interacts with poly(A) polymerase and other factors to facilitate cleavage and poly(A) addition. CPSF3 also possesses endonuclease activity, functioning as an mRNA 3'-end-processing endonuclease. Additionally, it participates in histone 3'-end pre-mRNA processing. CPSF3 acts as a U7 snRNP-dependent protein, inducing both the 3'-endoribonucleolytic cleavage of histone pre-mRNAs and acting as a 5' to 3' exonuclease to degrade the subsequent downstream cleavage product (DCP) of mature histone mRNAs. Cleavage occurs after the 5'-ACCCA-3' sequence in the histone pre-mRNA, leaving a 3' hydroxyl group on the upstream fragment containing the stem loop (SL) and a 5' phosphate on the downstream cleavage product (DCP) starting with CU nucleotides. The U7-dependent 5' to 3' exonuclease activity is processive and degrades the DCP RNA substrate even after complete removal of the U7-binding site. CPSF3 binds to the downstream cleavage product (DCP) of histone pre-mRNAs and the cleaved DCP RNA substrate in a U7 snRNP-dependent manner. It is required for entering/progressing through the S-phase of the cell cycle. CPSF3 is essential for the selective processing of microRNAs (miRNAs) during embryonic stem cell differentiation through its interaction with ISY1. It is also required for the biogenesis of all miRNAs from the pri-miR-17-92 primary transcript, except for miR-92a. CPSF3 is only required for the biogenesis of miR-290 and miR-96 from the pri-miR-290-295 and pri-miR-96-183 primary transcripts, respectively.
CPSF3 is also known as CPSF-73, CPSF73, NEDMHS, NEDMHSN.
