Elevated levels of homologous DNA recombination activity in the regenerating rat liver.
We have characterized homologous DNA recombination activity in nuclear protein extracts prepared from quiescent and regenerating rat livers. Activity measured in regenerating liver extracts was elevated approximately 35-fold above control, and its appearance closely mirrored the first wave of DNA synthesis, peaking 24 hours after a regenerative stimulus, and returning fairly rapidly to basal levels. We also identified a strand-transferase protein of approximately 100 kDa whose presence in these extracts correlates with homologous recombination activity. Recent evidence suggests that mammalian somatic cells possess a recombinational DNA repair mechanism analogous to that described in the yeast Saccharomyces cerevisiae. Our results indicate that this recombinational repair process may be regulated in vivo by, or play a role in, progression through the cell division cycle.
Thyagarajan
B
B
Department of Pharmacology, University of Minnesota Medical School, Minneapolis 55455, USA.
Cruise
J L
JL
Campbell
C
C
D000818:Animals; D002457:Cell Extracts; D002467:Cell Nucleus / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis / Q000235:genetics; D004254:DNA Nucleotidyltransferases / Q000737:chemistry; D004260:DNA Repair / Q000502:physiology; D005260:Female; D008115:Liver Regeneration / Q000235:genetics*; D008970:Molecular Weight; D051381:Rats; D011916:Rats, Inbred F344; D011995:Recombination, Genetic
D002457:Cell Extracts; D004247:DNA; D004254:DNA Nucleotidyltransferases