Physiological responses of the hyperthermophilic archaeon "Pyrococcus abyssi" to DNA damage caused by ionizing radiation.
The mechanisms by which hyperthermophilic Archaea, such as "Pyrococcus abyssi" and Pyrococcus furiosus, survive high doses of ionizing gamma irradiation are not thoroughly elucidated. Following gamma-ray irradiation at 2,500 Gy, the restoration of "P. abyssi" chromosomes took place within chromosome fragmentation. DNA synthesis in irradiated "P. abyssi" cells during the DNA repair phase was inhibited in comparison to nonirradiated control cultures, suggesting that DNA damage causes a replication block in this organism. We also found evidence for transient export of damaged DNA out of irradiated "P. abyssi" cells prior to a restart of chromosomal DNA synthesis. Our cell fractionation assays further suggest that "P. abyssi" contains a highly efficient DNA repair system which is continuously ready to repair the DNA damage caused by high temperature and/or ionizing radiation.
Jolivet
Edmond
E
Institut Universitaire Européen de la Mer, Université de Bretagne occidentale, CNRS UMR 6539, Technopôle Brest-Iroise, 29 280 Plouzané, France. jolivet@univ-brest.fr
Matsunaga
Fujihiko
F
Ishino
Yoshizumi
Y
Forterre
Patrick
P
Prieur
Daniel
D
Myllykallio
Hannu
H
D015153:Blotting, Western; D003470:Culture Media; D004249:DNA Damage; D004260:DNA Repair; D004261:DNA Replication; D005720:Gamma Rays / Q000009:adverse effects*; D006358:Hot Temperature; D019711:Pyrococcus / Q000254:growth & development / Q000502:physiology* / Q000528:radiation effects; D020027:Pyrococcus furiosus / Q000502:physiology / Q000528:radiation effects; D011839:Radiation, Ionizing
D003470:Culture Media