CTD Phosphatase 1 (CTDP1)

CTDP1 encodes a protein which interacts with the carboxy-terminus of transcription initiation factor TFIIF, a transcription factor which regulates elongation as well as initiation by RNA polymerase II. The protein may also represent a component of an RNA polymerase II holoenzyme complex. Alternative splicing of this gene results in two transcript variants encoding 2 different isoforms.One CTDP1 cDNA identified encodes a deduced 842-amino acid protein that the authors termed FCP1A. Another CTDP1 cDNA identified encodes a presumed splice variant, termed FCP1B, that lacks the last 139 amino acids. Northern blot analysis detected a 3.6-kb CTDP1 transcript in all tissues tested, namely heart, brain, placenta, lung, liver, skeletal muscle, kidney, and pancreas. Immunoblot analysis detected a 150-kD protein in HeLa nuclear extracts.