De novo phosphorylation of H2AX by WSTF regulates transcription-coupled homologous recombination repair

Abstract

Histone H2AX undergoes a phosphorylation switch from pTyr142 (H2AX-pY142) to pSer139 (γH2AX) in the DNA damage response (DDR); however, the functional role of H2AX-pY142 remains elusive. Here, we report a new layer of regulation involving transcription-coupled H2AX-pY142 in the DDR. We found that constitutive H2AX-pY142 generated by Williams-Beuren syndrome transcription factor (WSTF) interacts with RNA polymerase II (RNAPII) and is associated with RNAPII-mediated active transcription in proliferating cells. Also, removal of pre-existing H2AX-pY142 by ATM-dependent EYA1/3 phosphatases disrupts this association and requires for transcriptional silencing at transcribed active damage sites. The following recovery of H2AX-pY142 via translocation of WSTF to DNA lesions facilitates transcription-coupled homologous recombination (TC-HR) in the G1 phase, whereby RAD51 loading, but not RPA32, utilizes RNAPII-dependent active RNA transcripts as donor templates. We propose that the WSTF-H2AX-RNAPII axis regulates transcription and TC-HR repair to maintain genome integrity.

Single-Cell RNA Transcriptome Helps Define the Limbal/Corneal Epithelial Stem/Early Transit Amplifying Cells and How Autophagy Affects This Population

“…6E; Supplementary Table S3). Phosphorylation of histone H2AX is a well-known modification that regulates the DNA damage signaling pathway and maintains genome integrity 71–73. H2AX was minimally expressed in the limbal epithelium of wild-type mice and humans (Figs.…”

AR phosphorylation and CHK2 kinase activity regulates IR-stabilized AR–CHK2 interaction and prostate cancer survival

“…However, less foci are found in CHK2 knock-down cells at 2 hr and by 4 hr through 24 hr an equal number of foci are present in control and CHK2 knock-down cells. H2AX is phosphorylated in response to inputs in addition to IR induced DNA double strand breaks, including RNA polymerase II dependent transcription ( Singh et al, 2015 ; Bunch et al, 2015 ; Ji et al, 2019 ). Therefore, we also measured 53BP1 foci to assess DSB repair and found no significant differences when CHK2 was knocked down ( Figure 6C ).…”

“…However, when 53BP1 signal was measured to assess DSB repair we found no significant differences when CHK2 was knocked down. These conflicting results of γH2AX and 53BP1 signal may be explained by phosphorylation of H2AX in response to transcription induced DNA breaks ( Singh et al, 2015 ; Bunch et al, 2015 ; Ji et al, 2019 ). These incongruous results may also be due to competing effects of CHK2 as both a regulator of the cell cycle and apoptosis ( Zannini et al, 2014 ).…”

Kinases: The "Indispensables"of the DNA Damage Response Cascade

“…These were some of the classical NRTKs and their distinct roles in the DDR. Before we conclude, it is noteworthy to mention about the Williams syndrome transcription factor (WSTF) kinase which is neither a RTK nor a NRTK, but a bona fide TK which quite recently was shown to phosphorylate H2AX at Tyr 142 and induces transcription-coupled HR at DNA breaks [74].…”