Description
The CCAAT-box binding protein 1 (CTF1, also called NF-I or NF-1) is a proline-rich transcription activator. It selectively activates transcription of genes that contain GCCAAT consensus sequence in promoter region, including human Ha-Ras, alpha-globin, hsp70 and many other cellular and viral genes (1, 3-5). Cloning and functional characterization of the protein revealed that CTF1 contains an N-terminal DNA binding domain and a C-terminal proline-rich activation domain. CTF1 was shown to interact with the general transcription factor IIB (TFIIB) and facilitate the recruitment of TFIIB to TBP-DNA complexes, with the forkhead thyroid transcription factor TTF2 to regulate hormone–dependent transcription of thyroperoxidase gene, as well as other receptor proteins to synergize hormone receptor-responsive activation