Characterization of Pph3-mediated dephosphorylation of Rad53 during methyl methanesulfonate-induced DNA damage repair inCandida albicans.
Genotoxic stress causes DNA damage or stalled DNA replication and filamentous growth in the pathogenic fungusCandida albicansThe DNA checkpoint kinase Rad53 critically regulates by phosphorylation effectors that execute the stress response. Rad53 itself is activated by phosphorylation and inactivated by dephosphorylation. Previous studies have suggested that the phosphatase Pph3 dephosphorylates Rad53. Here, we used mass spectrometry and mutagenesis to identify Pph3 dephosphorylation sites on Rad53 inC. albicansWe found that serine residues 351, 461 and 477, which were dephosphorylated in wild-type cells during the recovery from DNA damage caused by methyl methanesulfonate (MMS), remained phosphorylated inpph3Δ/Δcells. Phosphomimetic mutation of the three residues (rad53-3D) impaired Rad53 dephosphorylation, exit from cell cycle arrest, dephosphorylation of two Rad53 effectors Dun1 and Dbf4, and the filament-to-yeast growth transition during the recovery from MMS-induced DNA damage. The phenotypes observed in therad53-3Dmutant also occurred in thepph3Δ/Δmutant. Together, our findings reveal a molecular mechanism by which Pph3 controls DNA damage response inC. albicans.
Key Laboratory of Cell Proliferation and Regulation, College of Life Sciences, Beijing Normal University, Beijing, China.
Guangyin
G
Yao
Key Laboratory of Cell Proliferation and Regulation, College of Life Sciences, Beijing Normal University, Beijing, China.
Junhua
J
Wan
Key Laboratory of Cell Proliferation and Regulation, College of Life Sciences, Beijing Normal University, Beijing, China.
Qizheng
Q
Liu
Key Laboratory of Cell Proliferation and Regulation, College of Life Sciences, Beijing Normal University, Beijing, China.
Chunhua
C
Mu
Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore jlsang@bnu.edu.cn mcbwangy@imcb.a-star.edu.sg.|Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
Yue
Y
Wang
Key Laboratory of Cell Proliferation and Regulation, College of Life Sciences, Beijing Normal University, Beijing, China jlsang@bnu.edu.cn mcbwangy@imcb.a-star.edu.sg.
Jianli
J
Sang
D002176:Candida albicans / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D064447:Checkpoint Kinase 2 / Q000235:genetics* / Q000378:metabolism; D004249:DNA Damage; D004260:DNA Repair; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D008741:Methyl Methanesulfonate / Q000494:pharmacology*; D010749:Phosphoprotein Phosphatases / Q000172:deficiency / Q000235:genetics*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D012694:Serine / Q000378:metabolism
D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D012694:Serine; D008741:Methyl Methanesulfonate; D064447:Checkpoint Kinase 2; D017346:Protein Serine-Threonine Kinases; D010749:Phosphoprotein Phosphatases
DNA damage repair; Rad53; phosphorylation/dephosphorylation