TY - JOUR AU - Kumar, Rakesh AB -

Although metastasis-associated protein 1 (MTA1), a component of the nucleosome remodeling and deacetylase (NuRD) complex, is a DNA-damage response protein and regulates p53-dependent DNA repair, it remains unknown whether MTA1 also participates in p53-independent DNA damage response. Here, we provide evidence that MTA1 is a p53-independent transcriptional corepressor of p21WAF1, and the underlying mechanism involves recruitment of MTA1-histone deacetylase 2 (HDAC2) complexes onto two selective regions of the p21WAF1 promoter. Accordingly, MTA1 depletion, despite its effect on p53 down-regulation, superinduces p21WAF1, increases p21WAF1 binding to proliferating cell nuclear antigen (PCNA), and decreases the nuclear accumulation of PCNA in response to ionizing radiation. In support of a p53-independent role of MTA1 in DNA damage response, we further demonstrate that induced expression of MTA1 in p53-null cells inhibits p21WAF1 promoter activity and p21WAF1 binding to PCNA. Consequently, MTA1 expression in p53-null cells results in increased induction of γH2AX foci and DNA double strand break repair, and decreased DNA damage sensitivity following ionizing radiation treatment. These findings uncover a new target of MTA1 and the existence of an additional p53-independent role of MTA1 in DNA damage response, at least in part, by modulating the p21WAF1-PCNA pathway, and thus, linking two previously unconnected NuRD complex and DNA-damage response pathways.

TI - Revelation of p53-independent Function of MTA1 in DNA Damage Response via Modulation of the p21WAF1-Proliferating Cell Nuclear Antigen Pathway * JF - Journal of Biological Chemistry DO - 10.1074/jbc.m109.079095 DA - 2010-03-26 UR - https://www.deepdyve.com/lp/american-society-for-biochemistry-and-molecular-biology/revelation-of-p53-independent-function-of-mta1-in-dna-damage-response-ZaOsK0sPiC SP - 10044 EP - 10052 VL - 285 IS - 13 DP - DeepDyve ER -