Spatiotemporal dynamics of p21CDKN1A protein recruitment to DNA-damage sites and interaction with proliferating cell nuclear antigen

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Item Type:	Article
Title:	Spatiotemporal dynamics of p21CDKN1A protein recruitment to DNA-damage sites and interaction with proliferating cell nuclear antigen
Creators Name:	Perucca, P., Cazzalini, O., Mortusewicz, O., Necchi, D., Savio, M., Nardo, T., Stivala, L.A., Leonhardt, H., Cardoso, M.C. and Prosperi, E.
Abstract:	The cyclin-dependent kinase inhibitor P21CDKN1A plays a fundamental role in the DNA-damage response by inducing cell-cycle arrest, and by inhibiting DNA replication through association with the proliferating cell nuclear antigen (PCNA). However, the role of such an interaction in DNA repair is poorly understood and controversial. Here, we provide evidence that a pool of p21 protein is rapidly recruited to UV-induced DNA-damage sites, where it colocalises with PCNA and PCNA-interacting proteins involved in nucleotide excision repair (NER), such as DNA polymerase {delta}, XPG and CAF-1. In vivo imaging and confocal fluorescence microscopy analysis of cells coexpressing p21 and PCNA fused to green or red fluorescent protein (p21-GFP, RFP-PCNA), showed a rapid relocation of both proteins at microirradiated nuclear spots, although dynamic measurements suggested that p21-GFP was recruited with slower kinetics. An exogenously expressed p21 mutant protein unable to bind PCNA neither colocalised, nor coimmunoprecipitated with PCNA after UV irradiation. In NER-deficient XP-A fibroblasts, p21 relocation was greatly delayed, concomitantly with that of PCNA. These results indicate that early recruitment of p21 protein to DNA-damage sites is a NER-related process dependent on interaction with PCNA, thus suggesting a direct involvement of p21 in DNA repair.
Keywords:	p21waf1/cip1, PCNA, DNA repair, Nucleotide excision repair, UV irradiation
Source:	Journal of Cell Science
ISSN:	0021-9533
Publisher:	Company of Biologists
Volume:	119
Number:	8
Page Range:	1517-1527
Date:	15 April 2006
Official Publication:	https://doi.org/10.1242/jcs.02868
PubMed:	View item in PubMed

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