title: Differential roles of tau class glutathione S-transferases in oxidative stress.
abstract: 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 was prooxidant-specific, indicating a different role for each LeGSTU in the oxidative stress-response 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 YAP1-dependent 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.
authors.affiliation: Mediterranean Agronomic Institute of Chania, Alsyllion Agrokepiou, Chania 73100, Greece.
authors.forename: Kimiti G
authors.initials: KG
authors.lastname: Kilili
authors.forename: Neli
authors.initials: N
authors.lastname: Atanassova
authors.forename: Alla
authors.initials: A
authors.lastname: Vardanyan
authors.forename: Nicolas
authors.initials: N
authors.lastname: Clatot
authors.forename: Khaled
authors.initials: K
authors.lastname: Al-Sabarna
authors.forename: Panagiotis N
authors.initials: PN
authors.lastname: Kanellopoulos
authors.forename: Antonios M
authors.initials: AM
authors.lastname: Makris
authors.forename: Sotirios C
authors.initials: SC
authors.lastname: Kampranis
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis; D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D005978:Glutathione / Q000737:chemistry / Q000378:metabolism; D019803:Glutathione Disulfide / Q000737:chemistry; D005982:Glutathione Transferase / Q000378:metabolism / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D018551:Solanum lycopersicum / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016877:Oxidants / Q000737:chemistry / Q000378:metabolism; D018384:Oxidative Stress; D010641:Phenotype; D011233:Precipitin Tests; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D020798:Two-Hybrid System Techniques; D051028:bcl-2-Associated X Protein
chemical_list: D016877:Oxidants; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D005982:Glutathione Transferase; D005978:Glutathione; D019803:Glutathione Disulfide