Tags: Protein.
Cleavage and polyadenylation specificity factor subunit 1 is a protein that in humans is encoded by the CPSF1 gene.In most cases eukaryotic pre-messenger(m)RNA 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(A) tail at the 3 prime end of the 5 prime cleavage product.