
<ArticleTitle>Interactions in the error-prone postreplication repair proteins <prot>hREV1</prot>, <prot>hREV3</prot>, and <prot>hREV7</prot>.</ArticleTitle>
<AbstractText>Most mutations after DNA damage in yeast Saccharomyces cerevisiae are induced by error-prone translesion DNA synthesis employing <prot>scRev1</prot> and <prot>DNA polymerase zeta</prot> that consists of <prot>scRev3</prot> and <prot>scRev7</prot> proteins. Recently, the human <prot>REV1</prot> (<prot>hREV1</prot>) and <prot>REV3</prot> (<prot>hREV3</prot>) genes were identified, and their products were revealed to be involved in UV-induced mutagenesis, as observed for their yeast counterparts. Human <prot>REV7</prot> (<prot>hREV7</prot>) was also cloned, and its product was found to interact with <prot>hREV3</prot>, but the biological function of <prot>hREV7</prot> remained unknown. We report here the analyses of precise interactions in the human <prot>REV</prot> proteins. The interaction between <prot>hREV1</prot> and <prot>hREV7</prot> was identified by the yeast two-hybrid library screening using a bait of <prot>hREV7</prot>, which was confirmed by in vitro and in vivo binding assays. The homodimerization of <prot>hREV7</prot> was also detected in the two-hybrid analysis. In addition, the precise domains for interaction between <prot>hREV7</prot> and <prot>hREV1</prot> or <prot>hREV3</prot> and for <prot>hREV7</prot> homodimerization were determined. Although <prot>hREV7</prot> interacts with both <prot>hREV1</prot> and <prot>hREV3</prot>, a stable complex formation of the three proteins was undetectable in vitro. These findings suggest the possibility that <prot>hREV7</prot> might play an important role in regulating the enzymatic activities of <prot>hREV1</prot> and <prot>hREV3</prot> for mutagenesis in response to DNA damage.</AbstractText>
