Distinct modes of DNA damage response in S. pombe G0 and vegetative cells.
Upon nitrogen-starvation, mostly G2 vegetative (VE) fission yeast cells promote two rounds of division and enter the G0 state with 1C DNA via an uncommitted G1. Whilst G0 cells are permanently arrested, they keep viability through recycling the intracellular nitrogen. We here show that, whilst the DNA damages are efficiently repaired in G0 cells, neither Chk1 activation nor Cdc2 implication for Crb2 (53BP1 like) do not occur. ATR-like Rad3 and non-hyperphosphorylated Crb2 participate the repair processes in G0 cells that are more sensitive to UV and gamma-ray than in VE cells. The sensitivity like in VE cells is restored after replication in the nitrogen-replenished medium, suggesting that the damage hyper-sensitive nature of G0 cells is due to the error-prone repair for single DNA duplex chromosome. The double-strand break (DSB) repair in G0 cells required Pku80, one of non-homologous end joining (NHEJ) proteins. S. pombe G0 cells upon DNA damages thus respond distinctively from VE cells in regard with regulation of checkpoint proteins and the mode of repair that is dependent upon the use of NHEJ.
Mochida
Satoru
S
The G0 Cell Unit, Initial Research Project (IRP), Okinawa Institute of Science and Technology (OIST) Corporation, 12-22 Suzaki, Uruma, Okinawa 904-2234, Japan.
Yanagida
Mitsuhiro
M
D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics; D000071877:Checkpoint Kinase 1; D004249:DNA Damage; D004261:DNA Replication; D005720:Gamma Rays; D005947:Glucose / Q000502:physiology; D008164:Luminescent Proteins / Q000737:chemistry / Q000235:genetics; D009584:Nitrogen / Q000378:metabolism; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics; D010766:Phosphorylation; D011494:Protein Kinases / Q000502:physiology; D016192:Resting Phase, Cell Cycle / Q000528:radiation effects*; D012568:Schizosaccharomyces / Q000166:cytology* / Q000254:growth & development / Q000528:radiation effects*; D029702:Schizosaccharomyces pombe Proteins / Q000737:chemistry / Q000235:genetics; D013455:Sulfur / Q000502:physiology; D013941:Thymine / Q000737:chemistry; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; C109867:Crb2 protein, S pombe; D008164:Luminescent Proteins; D009687:Nuclear Proteins; D029702:Schizosaccharomyces pombe Proteins; C054562:yellow fluorescent protein, Bacteria; D013455:Sulfur; D011494:Protein Kinases; D000071877:Checkpoint Kinase 1; C000605873:Chk1 protein, S pombe; D005947:Glucose; D009584:Nitrogen; D013941:Thymine