抄録
Ionizing radiation frequently causes oxidative DNA damage in cells. It has been suggested that functions of the REV1 and REV7 genes are induction of mutations and prevention of cell death caused by ionizing radiation. However, in higher eucaryotes, functions of homologues are poorly understood and appear somewhat different from the yeast case. It has been suggested that human REV1 interacts with human REV7, this being specific to higher eucaryotes. Here we show that purified human REV1 and REV7 proteins form a heterodimer in solution, which is stable through intensive purification steps. Results from biochemical analysis of the transferase reactions of the REV1-REV7 complex demonstrated, in contrast to the case of yeast Rev3 whose polymerase activity is stimulated by assembly with yeast Rev7, that human REV7 did not influence the stability, substrate specificity or kinetic parameters of the transferase reactions of REV1 protein. A possible molecular role of the REV7 subunit may be to help assembly of the REV1 protein to a large complex containing REV3 and/or other DNA polymerases in higher eucaryotes. [J Radiat Res 44:413 (2003)]
