The role of polo-like-kinase 1 in the survival of DNA repair deficient yeast, after genotoxic exposure to hexavalent chromium. Open Access
Downloadable ContentDownload PDF
Chromium occurs naturally in the environment and is a well-known human respiratory carcinogen. In the environment, chromium generally exists in two states; trivalent Cr(III) and hexavalent chromium Cr(VI). Of the two valence states, Cr(VI) is believed to be carcinogenic to humans and is believed to be related to genotoxicity causing a wide variety of DNA abnormalities. Polo-like-kinases (Plk's) are serine/threonine kinases that play a vital role in cell cycle progression and DNA damage response. Earlier studies have indicated that overexpression of mammalian Plk1 in yeast cells deficient in one of the two double strand break repair pathways enhances the survival of the cells after exposure to Cr(VI). The objective of this project was to evaluate the hypothesis that whether or not the overexpression of Plk1 in yeast cells deficient in both double strand repair pathways rescues the cells from Cr(VI) induced damage and enhances their survival. Our findings suggested that yeast cells deficient in both the repair pathways were found to be significantly sensitive towards the Cr(VI) damage as compared to the cells deficient in only one repair pathway. But the overexpression of mammalian Plk1 in the cells deficient in both repair pathways did not have any profound increase in the survival rates of the cells after exposure to Cr(VI) as hypothesized.