Expression of the human RAD51 gene during the cell cycle in primary human peripheral blood lymphocytes.
The S. cerevisiae RAD51 gene product exerts important functions in meiotic and mitotic recombination, as well as in the repair of DNA double-strand breaks. We have studied the expression of the human RAD51 (HsRAD51) gene in primary human peripheral blood lymphocytes (PBLs). The HsRAD51 mRNA level increased three fold in mitogen stimulated PBLs, with a peak in the late S phase. A five fold increase of HsRAD51 protein levels was observed in late G2. Specific inhibition of DNA synthesis with aphidicolin did not block the induction of the HsRAD51 protein, indicating that HsRAD51 expression is independent of DNA replication. In contrast, after inhibition of RNA synthesis with actinomycin D and protein synthesis with cycloheximide, the HsRAD51 protein level decreased rapidly. Taken together, these results indicate that the HsRAD51 gene is transcriptionally regulated in human PBLs, and exerts its function during the late S and G2 phases of the cell cycle.
Flygare
J
J
Department of Bioscience at Novum, Karolinska Institutet, Huddinge, Sweden.
Benson
F
F
Hellgren
D
D
D000199:Actins / Q000096:biosynthesis; D016590:Aphidicolin / Q000494:pharmacology; D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects; D002461:Cell Line, Transformed; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D015342:DNA Probes; D004268:DNA-Binding Proteins / Q000096:biosynthesis*; D003609:Dactinomycin / Q000494:pharmacology; D015870:Gene Expression; D006801:Humans; D007700:Kinetics; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis; D051135:Rad51 Recombinase; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins; D013601:T-Lymphocytes
D000199:Actins; D015342:DNA Probes; D004268:DNA-Binding Proteins; D018809:Proliferating Cell Nuclear Antigen; D029701:Saccharomyces cerevisiae Proteins; D003609:Dactinomycin; D016590:Aphidicolin; D004247:DNA; D003513:Cycloheximide; C495151:RAD51 protein, S cerevisiae; C495153:RAD51 protein, human; D051135:Rad51 Recombinase