Multiple roles of the proliferating cell nuclear antigen: DNA replication, repair and cell cycle control.

Abstract

The proliferating cell nuclear antigen (PCNA), the auxiliary protein of DNA polymerase delta and epsilon, is involved in DNA replication and repair. This protein forms a homotrimeric structure which, encircling DNA, loads the polymerase on the DNA template. A role for PCNA in the cell cycle control is recognised on the basis of the interaction with cyclins, cyclin-dependent kinases (cdks) and the cdk-inhibitor p21 waf1/cip1/sdi1 protein. Association with the growth-arrest and DNA-damage inducible proteins gadd45 and MyD118, further demonstrates the role of PCNA as a component of the cell cycle control apparatus.