Poly(ADP-ribose) polymerase 1 escorts XPC to UV-induced DNA lesions during nucleotide excision repair

Abstract

Xeroderma pigmentosum C (XPC) protein initiates the global genomic subpathway of nucleotide excision repair (GG-NER) for removal of UV-induced direct photolesions from genomic DNA. The XPC has an inherent capacity to identify and stabilize at the DNA lesion sites, and this function is facilitated in the genomic context by UV-damaged DNA-binding protein 2 (DDB2), which is part of a multiprotein UV-DDB ubiquitin ligase complex. The nuclear enzyme poly(ADP-ribose) polymerase 1 (PARP1) has been shown to facilitate the lesion recognition step of GG-NER via its interaction with DDB2 at the lesion site. Here, we show that PARP1 plays an additional DDB2-independent direct role in recruitment and stabilization of XPC at the UV-induced DNA lesions to promote GG-NER. It forms a stable complex with XPC in the nucleoplasm under steady-state conditions before irradiation and rapidly escorts it to the damaged DNA after UV irradiation in a DDB2-independent manner. The catalytic activity of PARP1 is not required for the initial complex formation with XPC in the nucleoplasm but it enhances the recruitment of XPC to the DNA lesion site after irradiation. Using purified proteins, we also show that the PARP1-XPC complex facilitates the handover of XPC to the UVlesion site in the presence of the UV-DDB ligase complex. Thus, the lesion search function of XPC in the genomic context is controlled by XPC itself, DDB2, and PARP1. Our results reveal a paradigm that the known interaction of many proteins with PARP1 under steady-state conditions could have functional significance for these proteins.

PARP1 Inhibition Augments UVB-Mediated Mitochondrial Changes—Implications for UV-Induced DNA Repair and Photocarcinogenesis

“…Early after UVB exposure, we detected PAR formation, reflecting PARP activity which was completely suppressed by PARP inhibition. We showed that loss of PARylation caused defective CPD repair compared to the UVB-irradiated cells suggesting impaired NER pathway as several PARP1-intercating partners (DDB1, DDB2, ATM, RAD51, ALC1, XPC) [89][90][91] have been described so far. Furthermore, PARP1 promotes the establishment of locally relaxed chromatin structure [92] to enable the removal of damaged DNA parts.…”

Tethering-facilitated DNA ‘opening’ and complementary roles of β-hairpin motifs in the Rad4/XPC DNA damage sensor protein

“…Here, we applied the tC o -tC nitro -based FLT-FRET approach to examine the solution conformations accessible to Rad4-DNA complexes when tethered to undamaged DNA. The In a broader sense, the DNA 'opening' of a given site facilitated by prolonged residence time at that site may help explain the mechanisms of XPC within and beyond NER that cannot be explained solely by lesion binding preferences of XPC (57)(58)(59)(60)(61)(62)(63)(64). In these cases, proteins interacting with XPC (e.g., UV-DDB or DNA glycosylases or PARP or transcription factors) and/or post-translational modifications on XPC could help 'stall' the protein on DNA and induce opening of otherwise non-cognate DNA.…”

PARP1 protects from benzo[a]pyrene diol epoxide-induced replication stress and mutagenicity

“…The previous studies analyzed the role of PARP1 in NER in response to UV-light-induced DNA damage (Pines et al 2012 ; Robu et al 2013 , 2017 ; Vodenicharov et al 2005 ). However, whether and how PARP1 and PARylation are involved in the cellular response to bulky DNA lesions caused by chemical compounds such as B[a]P metabolites is largely unexplored.…”

“…While the role of PARP1 in DNA strand break and base excision repair is well characterized, the understanding of its functions in response to bulky DNA lesions is only emerging. Recent studies suggested that PARP1 is an important factor for an efficient NER process and facilitates the removal of UV photoproducts (Fischer et al 2014 ; Pines et al 2012 ; Robu et al 2013 , 2017 ). PARP1 has been shown to physically interact with several factors of the NER machinery, to covalently or non-covalently modify them with PAR, and thus alter their functionality and subcellular localization.…”

“…Thus, CSB interacts with PARP1 and PAR, and its ATPase activity was reported to be inhibited upon this interaction (Scheibye-Knudsen et al 2014 ; Thorslund et al 2005 ). XPC is modified with PAR in a covalent and non-covalent manner and is recruited to damage sites in a PARP1- and PAR-dependent manner (Robu et al 2013 , 2017 ). XPA has been shown to interact with PARP1 and PAR, and this interaction functions as a reciprocal regulatory mechanism between the NER pathway and PARP1.…”