PROLIFERATING CELL NUCLEAR ANTIGEN - MORE THAN A CLAMP FOR DNA-POLYMERASES

DNA metabolic events such as replication, repair and recombination req uire the concerted action of several enzymes and cofactors. Nature has provided a set of proteins that support DNA polymerases in performing processive, accurate and rapid DNA synthesis. Two of them, the prolif erating cell nuclear antigen and its adapter protein replication facto r C, cooperate to form a moving platform that was initially thought of only as an anchor point for DNA polymerases delta and epsilon. It now appears that proliferating cell nuclear antigen is also a communicati on point between a variety of important cellular processes including c ell cycle control, DNA replication, nucleotide excision repair, post-r eplication mismatch repair, base excision repair and at least one apop totic pathway. The dynamic movement of proliferating cell nuclear anti gen on and off the DNA renders this protein an ideal communicator for a variety of proteins that are essential for DNA metabolic events in e ukaryotic cells.