Nek1 Regulates Rad54 to Orchestrate Homologous Recombination and Replication Fork Stability.
Never-in-mitosis A-related kinase 1 (Nek1) has established roles in apoptosis and cell cycle regulation. We show that human Nek1 regulates homologous recombination (HR) by phosphorylating Rad54 at Ser572 in late G2 phase. Nek1 deficiency as well as expression of unphosphorylatable Rad54 (Rad54-S572A) cause unresolved Rad51 foci and confer a defect in HR. Phospho-mimic Rad54 (Rad54-S572E), in contrast, promotes HR and rescues the HR defect associated with Nek1 loss. Although expression of phospho-mimic Rad54 is beneficial for HR, it causes Rad51 removal from chromatin and degradation of stalled replication forks in S phase. Thus, G2-specific phosphorylation of Rad54 by Nek1 promotes Rad51 chromatin removal during HR in G2 phase, and its absence in S phase is required for replication fork stability. In summary, Nek1 regulates Rad51 removal to orchestrate HR and replication fork stability.
Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany.
Julian
J
Spies
Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany.
Anja
A
Waizenegger
Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany.
Olivia
O
Barton
Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany.
Michael
M
Sürder
Section of Microbiology, University of California, Davis, Davis, CA 95616-8665, USA.
William D
WD
Wright
Section of Microbiology, University of California, Davis, Davis, CA 95616-8665, USA.
Wolf-Dietrich
WD
Heyer
Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany. Electronic address: lobrich@bio.tu-darmstadt.de.
Markus
M
Löbrich
D053903:DNA Breaks, Double-Stranded; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair; D004261:DNA Replication; D004268:DNA-Binding Proteins; D005347:Fibroblasts / Q000201:enzymology; D059565:G2 Phase Cell Cycle Checkpoints; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006367:HeLa Cells; D059765:Homologous Recombination; D006801:Humans; D009154:Mutation; D000072380:NIMA-Related Kinase 1 / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D034622:RNA Interference; D051135:Rad51 Recombinase / Q000235:genetics / Q000378:metabolism; D018741:Replication Origin; D059807:S Phase Cell Cycle Checkpoints; D012694:Serine; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012694:Serine; C000606914:NEK1 protein, human; D000072380:NIMA-Related Kinase 1; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; D004265:DNA Helicases; C103532:RAD54L protein, human