Target Information

PCNA (polymerase delta auxiliary protein) is essential for DNA replication and is involved in DNA excision and mismatch repair pathways. PCNA binds to the CDK inhibitor p21, the structure-specific endonucleases Fen1 and XPG, and DNA cytosine 5-methyltransferase (MCMT). PCNA is a potentially useful marker of cells with proliferative potential and for identifying the proliferation status of tumor tissue (i.e. relevant to prognosis). PCNA is a marker for cells in early G1 phase and S phase of the cell cycle. PCNA is found in the nucleus and is a cofactor of DNA polymerase delta, and acts as a homotrimer and helps increase the processing of leading strand synthesis during DNA replication. In response to DNA damage, PCNA is ubiquitinated and is involved in the RAD6-dependent DNA repair pathway. Two transcript variants encoding the same protein have been found for PCNA. Pseudogenes of PCNA have been described on chromosome 4 and on the X chromosome.