Regulation of nuclear pre-mRNA domain-containing protein 1B (RPRD1B)

Interacts with phosphorylated C-terminal heptapeptide repeat domain (CTD) of the largest RNA polymerase II subunit POLR2A, and participates in dephosphorylation of the CTD by RPAP2. Transcriptional regulator which enhances expression of CCND1.

Promotes binding of RNA polymerase II into the CCDN1 promoter and to the termination area before the poly-A site but decreases its binding following the poly-A site. Prevents RNA polymerase II from reading through the 3' end termination site and may let it be recruited back to the promoter through promotion of the formation of a chromatin loop.