Chromosome Transmission Fidelity Protein 18 (CHTF18)

CHTF18, CHTF8, and DCC1 (DSCC1) are components of an alternative replication factor C (RFC) complex that loads PCNA onto DNA during S phase of the cell cycle. The deduced protein has a calculated molecular mass of 110 kD. It has an N- terminal nuclear localization signal, followed by a proline-rich domain, an NTPase domain with an NTP-binding motif, a central RFC conserved domain, an ankyrin repeat domain, and 2 C-terminal leucine zipper motifs. The expression of CHTF18 and DCC1 increased in synchronized T24 bladder carcinoma cells during S phase. Immunohistochemical analysis showed that CHTF18, CHTF8, and DCC1 localized to nuclear heterochromatin in a diffuse manner and appeared less abundant in nucleoli. SDS/PAGE analysis detected CHTF18 with an apparent molecular mass of about 110 kD.