The hinge domain of cleavage stimulation factor subunit 2 proteins, CSTF2, is necessary for binding to the subunit CstF-77 within the polyadenylation complex and subsequent nuclear localisation. This suggests that nuclear import of a pre-formed CSTF complex is an essential step in polyadenylation. Accurate and efficient polyadenylation is essential for transcriptional termination, nuclear export, translation, and stability of eukaryotic mRNAs. CSTF2 is an important regulatory subunit of the polyadenylation complex.

1: The hinge domain of the cleavage stimulation factor protein CstF-64 is essential for CstF-77 interaction, nuclear localization, and polyadenylation. Hockert JA, Yeh HJ, MacDonald CC; J Biol Chem. 2010;285:695-704. PMID:19887456