Dynamic control of Rad51 recombinase by self-association and interaction with BRCA2.
Here, we visualize GFP-Rad51 fusion proteins in the nucleus of living cells to demonstrate the dynamic compartmentalization of Rad51 by self-association or by binding to BRCA2. Mutants of Rad51 that fail to oligomerize and/or to bind BRCA2 distinguish three fractions of Rad51 within the nucleoplasm: a relatively mobile fraction, an immobile oligomerized fraction, and an immobile BRCA2-bound fraction. Strikingly, inhibition of replication by hydroxyurea reduces the immobile fraction of nucleoplasmic Rad51. This effect is specific to Rad51 mutants that retain the capacity to bind BRCA2, indicating that the BRCA2-bound fraction is selectively mobilized. We propose that arrested replication triggers a switch between dual functions of BRCA2 in sequestering or mobilizing a small fraction of nucleoplasmic Rad51 and suggest a mechanism for the dynamic control of protein complexes that participate in homologous recombination.
CR UK Department of Oncology and The Medical Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, Hills Road, Cambridge CB2 2XZ, United Kingdom.
David S
DS
Yu
Eiichiro
E
Sonoda
Shunichi
S
Takeda
Christopher L H
CL
Huang
Luca
L
Pellegrini
Tom L
TL
Blundell
Ashok R
AR
Venkitaraman
D000818:Animals; D030161:Avian Proteins; D024682:BRCA2 Protein / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites / Q000187:drug effects / Q000235:genetics; D002451:Cell Compartmentation / Q000235:genetics*; D002455:Cell Division / Q000187:drug effects / Q000235:genetics; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology* / Q000235:genetics; D004261:DNA Replication / Q000187:drug effects / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006918:Hydroxyurea / Q000494:pharmacology; D046911:Macromolecular Substances; D009154:Mutation / Q000235:genetics; D011485:Protein Binding / Q000235:genetics; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D051135:Rad51 Recombinase; D011993:Recombinant Fusion Proteins / Q000494:pharmacology; D011995:Recombination, Genetic / Q000235:genetics*
D030161:Avian Proteins; D024682:BRCA2 Protein; C447900:BRCA2 protein, chicken; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D021122:Protein Subunits; D011993:Recombinant Fusion Proteins; C495150:RAD51 protein, Gallus gallus; D051135:Rad51 Recombinase; D006918:Hydroxyurea