CPSF1
Cleavage and polyadenylation specificity factor subunit 1 is a protein that in humans is encoded by the CPSF1 gene.
In most cases eukaryotic pre-messengerRNA 3 prime ends are processed in two coordinated steps. First there is a site-specific cleavage by an endonuclease and then the addition of a poly tail at the 3 prime end of the 5 prime cleavage product. Cleavage requires four multisubunit complexes, namely cleavage and polyadenylation specificity factor, cleavage stimulation factor, cleavage factors Im and IIm, along with a single subunit polypolymerase. CPSF1 is the largest component of the CPSF complex composed of CPSF1, CPSF2, CPSF3, CPSF4, FIP1L1, Symplekin and WDR33 and located in the nucleus.
