High impact information on GSH2

• Arabidopsis plants treated with cadmium or copper responded by increasing transcription of the genes for glutathione synthesis, gamma-glutamylcysteine synthetase and glutathione synthetase, as well as glutathione reductase [1].
• Glutathione synthetase (GS) catalyzes the ATP-dependent formation of the ubiquitous peptide glutathione from gamma-glutamylcysteine and glycine [2].
• The bacterial and eukaryotic GS form two distinct families lacking amino acid sequence homology [2].
• Genetic or pharmacological inhibition of glutathione biosynthesis led to the elevated expression of AtATM3, whereas expression of the glutathione synthase gene GSH1 was increased under Cd(II) stress and in the atatm3 mutant [3].
• The genome of Arabidopsis thaliana reveals that in this species the enzymes of glutathione biosynthesis, GSH1 and GSH2, are encoded by single genes [4].

Biological context of GSH2

• The yeast gsh2 mutant becomes resistant to methylglyoxal and cadmium after transformation with the plasmid bearing the Arabidopsis GSH2 cDNA [5].
• When the Arabidopsis cDNA cloned in a special shuttle vector was expressed in a S. pombe mutant deficient in glutathione synthetase activity, the plant cDNA was able to complement the yeast mutation [6].

Anatomical context of GSH2

• As expected, the large (but less abundant) transcript encoded a plastidic GSH2 protein, whereas GSH2 synthesized from the shorter transcript was targeted to the cytosol [4].

Associations of GSH2 with chemical compounds

• Differential targeting of GSH1 and GSH2 is achieved by multiple transcription initiation: implications for the compartmentation of glutathione biosynthesis in the Brassicaceae [4].
• These data strongly suggest that the GSH2 gene encodes a bifunctional enzyme that is able to catalyse both the synthesis of GSH by adding glycine to the dipeptide (gammaGlu-Cys) and the synthesis of phytochelatins [7].

Other interactions of GSH2

• In vitro enzyme assays showed that the cad2-1 mutant has 40% of wild-type levels of GCS activity but is unchanged in the activity of the second enzyme in the pathway, GSH synthetase [8].

Analytical, diagnostic and therapeutic context of GSH2

• AtGSHS is encoded by a single gene, GSHB, as determined by Southern blot analysis and the corresponding mRNA is abundant in both roots and leaves of Arabidopsis [9].
• Glutathione synthetase catalyses the ATP-dependent ligation of gamma-glutamylcystene with glycine to form glutathione [10].
• Sequence analysis revealed that it encodes the second enzyme involved in glutathione (GSH) biosynthesis, glutathione synthetase (GSH2) (E.C.6.3.2.3, Wang and Oliver, 1997) [7].

References