The glutathione transferase kappa family

Abstract

Glutathione transferase (GST) kappa, also named mitochondrial GST, is a very ancient protein family with orthologs in bacteria and eukaryotes. Both the structure and the subcellular localization of GSTK1-1, in mitochondria and peroxisomes, make this enzyme distinct from cytosolic GSTs. Rodent and human GSTK1 exhibit activity towards a number of model GST substrates and, in Caenorhabditis elegans, this enzyme may be involved in energy and lipid metabolism, two functions related to mitochondria and peroxisomes. Interestingly, GST kappa is also a key regulator of adiponectin biosynthesis and multimerization suggesting that it might function as a chaperone to facilitate correct folding and assembly of proteins. Since adiponectin expression has been correlated with insulin resistance, obesity and diabetes, GSTK1 expression level which is negatively correlated with obesity in mice and human adipose tissues may be an important factor in these metabolic disorders. Furthermore, a polymorphism in the hGSTK1 promoter has been associated with insulin secretion and fat deposition.

Keywords::

• 2-hydroxychromene-2-carboxylic acid isomerase
• adiponectin
• gene expression
• glutathione transferase kappa
• lipid metabolism
• mitochondria
• peroxisome
• polymorphisms
• protein-protein interaction

Acknowledgements

Research support from the Institut National de la Santé et de la recherché Médicale and the Association pour la Recherche sur le Cancer is greatefully acknowledged. The authors thank Drs. A. Guillouzo and B. Fromenty for helpful comments and critical reading of the manuscript and wish to express their thanks to Mrs C. Rauch for technical assistance.

Declaration of interests

The authors report no declarations of interest.