Differential roles of tau class glutathione S-transferases in oxidative stress.
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.
Kilili
Kimiti G
KG
Mediterranean Agronomic Institute of Chania, Alsyllion Agrokepiou, Chania 73100, Greece.
Atanassova
Neli
N
Vardanyan
Alla
A
Clatot
Nicolas
N
Al-Sabarna
Khaled
K
Kanellopoulos
Panagiotis N
PN
Makris
Antonios M
AM
Kampranis
Sotirios C
SC
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
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