Cleavage and polyadenylation specificity factor

Cleavage and polyadenylation specificity factor (CPSF) (or Cleavage polyadenylation stimulating factor) is involved in the cleavage of the 3' signaling region from a newly synthesized pre-messenger RNA (pre-mRNA) molecule in the process of gene transcription. It is the first protein to bind to the signaling region near the cleavage site of the pre-mRNA, to which the polyadenine tail will be added by polyadenine polymerase. The upstream signaling region has the canonical nucleotide sequence AAUAAA, which is highly conserved across the vast majority of pre-mRNAs. A second downstream signaling region, located on the portion of the pre-mRNA that is cleaved before polyadenylation, consists of a GU-rich region required for efficient processing.

CPSF is a protein complex consisting of four proteins: CPSF-73, CPSF-100, CPSF-30 and CPSF-160. CPSF-73 is believed to be the endonuclease which cleaves mRNA precursor and the crystal structure of its N-terminal domain has been resolved. CPSF recruits additional proteins to the 3' region. Identified proteins that are coordinated by CPSF activity include: cleavage stimulatory factor and the two poorly-understood cleavage factors. The binding of the polyadenine polymerase responsible for actually synthesizing the tail is a necessary prerequisite for cleavage, thus ensuring that cleavage and polyadenylation are tightly coupled processes.

Genes

• CPSF1, CPSF2, CPSF3, CPSF4, CPSF6

References

• Lodish H, Berk A, Matsudaira P, Kaiser CA, Krieger M, Scott MP, Zipursky SL, Darnell J. (2004). Molecular Cell Biology. WH Freeman: New York, NY. 5th ed.
• Murthy KG, Manley JL. (1995). The 160-kD subunit of human cleavage-polyadenylation specificity factor coordinates pre-mRNA 3'-end formation. Gene Dev 9: 2672-2683.

External links

• MeSH Cleavage+And+Polyadenylation+Specificity+Factor