A novel checkpoint mechanism regulating the G1/S transition.
Ultraviolet irradiation of fission yeast cells in G1 phase induced a delay in chromatin binding of replication initiation factors and, consistently, a transient delay in S-phase entry. The cell cycle delay was totally dependent on the Gcn2 kinase, a sensor of the nutritional status, and was accompanied by phosphorylation of the translation initiation factor eIF2alpha and by a general depression of translation. However, the G1-specific synthesis of factors required for DNA replication was not reduced by ultraviolet radiation. The cell cycle delay represents a novel checkpoint with a novel mechanism of action that is not activated by ionizing radiation.
Tvegård
Tonje
T
Department of Cell Biology, Rikshospitalet-Radiumhospitalet Medical Centre and University of Oslo, Montebello, 0310 Oslo, Norway.
Soltani
Héla
H
Skjølberg
Henriette C
HC
Krohn
Marit
M
Nilssen
Esben A
EA
Kearsey
Stephen E
SE
Grallert
Beáta
B
Boye
Erik
E
D018797:Cell Cycle Proteins / Q000378:metabolism; D004789:Enzyme Activation / Q000528:radiation effects; D015852:Eukaryotic Initiation Factor-2 / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D016193:G1 Phase / Q000528:radiation effects; D064151:Minichromosome Maintenance Complex Component 6; D051738:Origin Recognition Complex / Q000378:metabolism; D010766:Phosphorylation / Q000528:radiation effects; D014176:Protein Biosynthesis / Q000528:radiation effects; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D016196:S Phase / Q000528:radiation effects; D012568:Schizosaccharomyces / Q000166:cytology* / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000528:radiation effects; D014466:Ultraviolet Rays
D018797:Cell Cycle Proteins; D015852:Eukaryotic Initiation Factor-2; D051738:Origin Recognition Complex; D029702:Schizosaccharomyces pombe Proteins; D017346:Protein Serine-Threonine Kinases; D064151:Minichromosome Maintenance Complex Component 6; C085710:mcm2 protein, S pombe; C092300:mcm6 protein, S pombe