Human Cleavage Stimulation Factor Subunit 1 (CSTF1) Protein

Background

Cleavage stimulation factor subunit 1 (CSTF1) is a component of the cleavage stimulation factor (CstF) complex, which is crucial for the polyadenylation and 3' end cleavage of pre-mRNAs. CSTF1 contains transducin-like WD40 repeats and functions as a homodimer within the CstF complex. It interacts directly with CSTF2 and CSTF3 to form the heterotrimeric CstF complex, which assembles on the pre-mRNA to facilitate cleavage and subsequent polyadenylation. CSTF1 is responsible for mediating interactions between CstF and other factors, ensuring the formation of a stable complex on the pre-mRNA. The expression levels of CstF components, including CSTF1, vary during the cell cycle, increasing significantly during the transition from G0 to S phase, indicating a role in cell cycle-regulated mRNA processing. Additionally, CSTF1 has been shown to interact with BARD1, linking mRNA 3' end formation to DNA damage response and tumor suppression pathways.