TY - JOUR
T1 - Recruitment of RBM6 to DNA Double-Strand Breaks Fosters Homologous Recombination Repair
AU - Awwad, Samah W.
AU - Darawshe, Malak M.
AU - Machour, Feras E.
AU - Arman, Inbar
AU - Ayoub, Nabieh
N1 - Publisher Copyright:
© 2023 Taylor & Francis Group, LLC.
PY - 2023
Y1 - 2023
N2 - DNA double-strand breaks (DSBs) are highly toxic lesions that threaten genome integrity and cell survival. To avoid harmful repercussions of DSBs, a wide variety of DNA repair factors are recruited to execute DSB repair. Previously, we demonstrated that RBM6 splicing factor facilitates homologous recombination (HR) of DSB by regulating alternative splicing-coupled nonstop-decay of the HR protein APBB1/Fe65. Here, we describe a splicing-independent function of RBM6 in promoting HR repair of DSBs. We show that RBM6 is recruited to DSB sites and PARP1 activity indirectly regulates RBM6 recruitment to DNA breakage sites. Deletion mapping analysis revealed a region containing five glycine residues within the G-patch domain that regulates RBM6 accumulation at DNA damage sites. We further ascertain that RBM6 interacts with Rad51, and this interaction is attenuated in RBM6 mutant lacking the G-patch domain (RBM6del(G-patch)). Consequently, RBM6del(G-patch) cells exhibit reduced levels of Rad51 foci after ionizing radiation. In addition, while RBM6 deletion mutant lacking the G-patch domain has no detectable effect on the expression levels of its splicing targets Fe65 and Eya2, it fails to restore the integrity of HR. Altogether, our results suggest that RBM6 recruitment to DSB promotes HR repair, irrespective of its splicing activity.HIGHLIGHTS PARP1 activity indirectly regulates RBM6 recruitment to DNA damage sites. Five glycine residues within the G-patch domain of RBM6 are critical for its recruitment to DNA damage sites, but dispensable for its splicing activity. RBM6 G-patch domain fosters its interaction with Rad51 and promotes Rad51 foci formation following irradiation. RBM6 recruitment to DSB sites underpins HR repair.
AB - DNA double-strand breaks (DSBs) are highly toxic lesions that threaten genome integrity and cell survival. To avoid harmful repercussions of DSBs, a wide variety of DNA repair factors are recruited to execute DSB repair. Previously, we demonstrated that RBM6 splicing factor facilitates homologous recombination (HR) of DSB by regulating alternative splicing-coupled nonstop-decay of the HR protein APBB1/Fe65. Here, we describe a splicing-independent function of RBM6 in promoting HR repair of DSBs. We show that RBM6 is recruited to DSB sites and PARP1 activity indirectly regulates RBM6 recruitment to DNA breakage sites. Deletion mapping analysis revealed a region containing five glycine residues within the G-patch domain that regulates RBM6 accumulation at DNA damage sites. We further ascertain that RBM6 interacts with Rad51, and this interaction is attenuated in RBM6 mutant lacking the G-patch domain (RBM6del(G-patch)). Consequently, RBM6del(G-patch) cells exhibit reduced levels of Rad51 foci after ionizing radiation. In addition, while RBM6 deletion mutant lacking the G-patch domain has no detectable effect on the expression levels of its splicing targets Fe65 and Eya2, it fails to restore the integrity of HR. Altogether, our results suggest that RBM6 recruitment to DSB promotes HR repair, irrespective of its splicing activity.HIGHLIGHTS PARP1 activity indirectly regulates RBM6 recruitment to DNA damage sites. Five glycine residues within the G-patch domain of RBM6 are critical for its recruitment to DNA damage sites, but dispensable for its splicing activity. RBM6 G-patch domain fosters its interaction with Rad51 and promotes Rad51 foci formation following irradiation. RBM6 recruitment to DSB sites underpins HR repair.
KW - G-patch domain
KW - PARP1
KW - RBM6
KW - Rad51
KW - double-strand breaks
KW - homologous recombination repair
UR - http://www.scopus.com/inward/record.url?scp=85150517392&partnerID=8YFLogxK
U2 - 10.1080/10985549.2023.2187105
DO - 10.1080/10985549.2023.2187105
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AN - SCOPUS:85150517392
SN - 0270-7306
VL - 43
SP - 130
EP - 142
JO - Molecular and Cellular Biology
JF - Molecular and Cellular Biology
IS - 3
ER -