Glutathione-S-transferases are major cytosolic thyroid hormone binding proteins.
Thyroid hormone binding proteins of rat liver cytosol were characterized. Glutathione-S-transferases were identified among major cytosolic proteins adsorbed by thyroxine affinity matrices. The Ya and Yb subunits of the glutathione-S-transferases were also principal proteins of cytosol covalently labeled with 3,3',5-triiodo-L-thyronine (T3) or 3,3',5,5'-tetraiodo-L-thyronine (T4) by photoaffinity methods. T3 and T4, but not L-thyronine or iodinated tyrosines, were bound with high affinity to purified glutathione-S-transferases and were potent inhibitors of their enzymatic activities. These results suggest that glutathione-S-transferases have the potential to function in the intracellular binding and transport of thyroid hormones. The proteins provide a means for regulating the action and metabolism of thyroid hormones by acting as high capacity binding components.
Ishigaki
S
S
Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461.
Abramovitz
M
M
Listowsky
I
I
D000345:Affinity Labels; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002846:Chromatography, Affinity; D002942:Circular Dichroism; D003600:Cytosol / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005982:Glutathione Transferase / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism; D008099:Liver / Q000201:enzymology; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013963:Thyroid Hormones / Q000378:metabolism; D000097810:Thyroid Hormone-Binding Proteins
D000345:Affinity Labels; D002352:Carrier Proteins; D005982:Glutathione Transferase; D007527:Isoenzymes; D008565:Membrane Proteins; D013963:Thyroid Hormones; D000097810:Thyroid Hormone-Binding Proteins