TY - JOUR
T1 - RAD51AP1 mediates RAD51 activity through nucleosome interaction
AU - Pires, Elena
AU - Sharma, Neelam
AU - Selemenakis, Platon
AU - Wu, Bo
AU - Huang, Yuxin
AU - Alimbetov, Dauren S.
AU - Zhao, Weixing
AU - Wiese, Claudia
N1 - Funding Information:
This work was supported by National Institutes of Health Grants R01ES021454, R56ES021454, R03ES029206 (to C. W.), a V Foundation Scholar Grant and a Max & Minnie Tomerlin Voelcker Young Investigator Award (to W. Z.). E. P. was cosupported by T32OD012201. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Funding Information:
Funding and additional information—This work was supported by National Institutes of Health Grants R01ES021454, R56ES021454, R03ES029206 (to C. W.), a V Foundation Scholar Grant and a Max & Minnie Tomerlin Voelcker Young Investigator Award (to W. Z.). E. P. was cosupported by T32OD012201. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Publisher Copyright:
© 2021 THE AUTHORS.
PY - 2021/7/1
Y1 - 2021/7/1
N2 - RAD51-associated protein 1 (RAD51AP1) is a key protein in the homologous recombination (HR) DNA repair pathway. Loss of RAD51AP1 leads to defective HR, genome instability, and telomere erosion. RAD51AP1 physically interacts with the RAD51 recombinase and promotes RAD51-mediated capture of donor DNA, synaptic complex assembly, and displacement-loop formation when tested with nucleosome-free DNA substrates. In cells, however, DNA is packaged into chromatin, posing an additional barrier to the complexities of the HR reaction. In this study, we show that RAD51AP1 binds to nucleosome core particles (NCPs), the minimum basic unit of chromatin in which approximately two superhelical turns of 147 bp double-stranded DNA are wrapped around one histone octamer with no free DNA ends remaining. We identified a C-terminal region in RAD51AP1, including its previously mapped DNA-binding domain, as critical for mediating the association between RAD51AP1 and both the NCP and the histone octamer. Using in vitro surrogate assays of HR activity, we show that RAD51AP1 is capable of promoting duplex DNA capture and initiating joint-molecule formation with the NCP and chromatinized template DNA, respectively. Together, our results suggest that RAD51AP1 directly assists in the RAD51-mediated search for donor DNA in chromatin. We present a model, in which RAD51AP1 anchors the DNA template through affinity for its nucleosomes to the RAD51-ssDNA nucleoprotein filament.
AB - RAD51-associated protein 1 (RAD51AP1) is a key protein in the homologous recombination (HR) DNA repair pathway. Loss of RAD51AP1 leads to defective HR, genome instability, and telomere erosion. RAD51AP1 physically interacts with the RAD51 recombinase and promotes RAD51-mediated capture of donor DNA, synaptic complex assembly, and displacement-loop formation when tested with nucleosome-free DNA substrates. In cells, however, DNA is packaged into chromatin, posing an additional barrier to the complexities of the HR reaction. In this study, we show that RAD51AP1 binds to nucleosome core particles (NCPs), the minimum basic unit of chromatin in which approximately two superhelical turns of 147 bp double-stranded DNA are wrapped around one histone octamer with no free DNA ends remaining. We identified a C-terminal region in RAD51AP1, including its previously mapped DNA-binding domain, as critical for mediating the association between RAD51AP1 and both the NCP and the histone octamer. Using in vitro surrogate assays of HR activity, we show that RAD51AP1 is capable of promoting duplex DNA capture and initiating joint-molecule formation with the NCP and chromatinized template DNA, respectively. Together, our results suggest that RAD51AP1 directly assists in the RAD51-mediated search for donor DNA in chromatin. We present a model, in which RAD51AP1 anchors the DNA template through affinity for its nucleosomes to the RAD51-ssDNA nucleoprotein filament.
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U2 - 10.1016/j.jbc.2021.100844
DO - 10.1016/j.jbc.2021.100844
M3 - Article
C2 - 34058198
AN - SCOPUS:85108686662
VL - 297
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 1
M1 - 100844
ER -