Interacts with phosphorylated C-terminal heptapeptide
repeat domain (CTD) of the largest RNA polymerase II subunit
POLR2A, and participates in dephosphorylation of the CTD.
Transcriptional regulator which enhances expression of CCND1.
Promotes binding of RNA polymerase II to the CCDN1 promoter and to
the termination region before the poly-A site but decreases its
binding after the poly-A site. Prevents RNA polymerase II from
reading through the 3' end termination site and may allow it to be
recruited back to the promoter through promotion of the formation
of a chromatin loop. Also enhances the transcription of a number of
other cell cycle-related genes including CDK2, CDK4, CDK6 and
cyclin-E but not CDKN1A, CDKN1B or cyclin-A. Promotes cell proliferation.