Cleavage and polyadenylation specificity factor
Encyclopedia
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 factor
s. 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.
Cleavage
Cleavage may refer to:*Cleavage , partial exposure of the separation between a woman's breasts.**Cleavage enhancement, methods of making a person's breast cleavage look more substantial than it really is....
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
Messenger RNA
Messenger RNA is a molecule of RNA encoding a chemical "blueprint" for a protein product. mRNA is transcribed from a DNA template, and carries coding information to the sites of protein synthesis: the ribosomes. Here, the nucleic acid polymer is translated into a polymer of amino acids: a protein...
(pre-mRNA) molecule in the process of gene transcription
Transcription (genetics)
Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...
. It is the first protein to bind to the signaling region near the cleavage site of the pre-mRNA, to which the polyadenine tail
Polyadenylation
Polyadenylation is the addition of a poly tail to an RNA molecule. The poly tail consists of multiple adenosine monophosphates; in other words, it is a stretch of RNA that has only adenine bases. In eukaryotes, polyadenylation is part of the process that produces mature messenger RNA for translation...
will be added by polyadenine polymerase. The upstream signaling region has the canonical nucleotide
Nucleotide
Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...
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
Protein complex
A multiprotein complex is a group of two or more associated polypeptide chains. If the different polypeptide chains contain different protein domain, the resulting multiprotein complex can have multiple catalytic functions...
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
Cleavage stimulatory factor
Cleavage stimulatory factor or cleavage stimulation factor is a heterotrimeric protein of about 200 kilodaltons that is involved in the cleavage of the 3' signaling region from a newly synthesized pre-messenger RNA molecule...
and the two poorly-understood cleavage factor
Cleavage factor
Cleavage factors are two closely related proteins involved in the cleavage of the 3' signaling region from a newly synthesized pre-messenger RNA molecule in the process of gene transcription. The cleavage is the first step in adding a polyadenine tail to the pre-mRNA, which is one of the necessary...
s. 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.