Differential Roles of Tau Class GlutathioneS-Transferases in Oxidative Stress

Kimiti G. Kilili, Neli Atanassova, Alla Vardanyan, Nicolas Clatot, Khaled Al-Sabarna, Panagiotis N. Kanellopoulos, Antonios M. Makris, Sotirios C. Kampranis
2004 Journal of Biological Chemistry  
The plant glutathione S-transferase BI-GST has been identified as a potent inhibitor of Bax lethality in yeast, a phenotype associated with oxidative stress and disruption of mitochondrial functions. Screening of a tomato two-hybrid library for BI-GST interacting proteins identified five homologous Tau class GSTs, which readily form heterodimers between them and BI-GST. All six LeGSTUs were found to be able to protect yeast cells from prooxidant-induced cell death. The efficiency of each LeGSTU
more » ... was prooxidant-specific, indicating a different role for each LeGSTU in the oxidative stressresponse mechanism. The prooxidant protective effect of all six proteins was suppressed in the absence of YAP1, a transcription factor that regulates hydroperoxide homeostasis in Saccharomyces cerevisiae, suggesting a role for the LeGSTUs in the context of the YAP1dependent stress-responsive machinery. The different LeGSTUs exhibited varied substrate specificity and showed activity against oxidative stress by-products, indicating that their prooxidant protective function is likely related to the minimization of oxidative damage. Taken together, these results indicate that Tau class GSTs participate in a broad network of catalytic and regulatory functions involved in the oxidative stress response.
doi:10.1074/jbc.m309882200 pmid:15037622 fatcat:iouf3lz3bbafnlxm4hjq2ofg64