PCNA/cyclin: a lupus antigen connected with DNA replication.

Molecular analysis of the proliferating cell nuclear antigen (PCNA) has the 2-fold goal of utilizing the unique tools provided by autoimmune sera to study the function of this important intracellular molecule and to provide insights into the etiology of autoimmune disease. PCNA is expressed in the nucleus immediately preceding S phase and, during S phase is colocalized with sites of active DNA synthesis. There is currently available not only a battery of human sera which can be rendered monospecific for PCNA, but also monoclonal antibodies and rabbit antipeptide antibodies. With these reagents, it might be possible to isolate cDNA clones from cDNA expression libraries.