Evidence for the Presence of Active and Inactive Forms of Cytosolic Triiodothyronine Binding Protein in Rat Kidney: Cooperative Action of Ca2+ in NADPH Activation.
- 1 January 1987
- journal article
- research article
- Published by Japan Endocrine Society in Endocrinologia Japonica
- Vol. 34 (4), 479-487
- https://doi.org/10.1507/endocrj1954.34.479
Abstract
The effect of NADPH and Ca2+ on 3, 5, 3''-L-triiodothyronine (T3) binding to cytosolic T3 binding protein (CTBP) in rat kidney was investigated in vitro. Extraction of rat kidney cytosol with 10% charcoal at 4.degree. C for 30 min. inactivated specific T3 binding. The decreased T3 binding activity in extracted cytosol could be restored by adding NADPH or Ca2+ to the incubation medium. Each substance increased the capacity for T3 without changes in the affinity for T3. The T3 binding was maximally increased by 25 .mu.M NADPH or by 1.0 mM Ca2+ in the presence of 0.1 mM EDTA. The increase in T3 binding, induced by 25 .mu.M NADPH, was enhanced by adding 0.2-1.0 mM Ca2+ in a concentration dependent-manner. The increase in T3 binding, induced by 1.0 mM Ca2+, was also enhanced by adding 3.125-25.0 .mu.M NADPH. The NADPH-induced increase in T3 binding capacity was amplified by Ca2+ in a multiplicative manner. The results suggested that Ca2+ cooperatively augmented an NADPH function in cytosolic T3 binding.This publication has 12 references indexed in Scilit:
- The effect of thyroid hormone on the high affinity Ca2+-ATPase in rat liver plasma membrane.Endocrinologia Japonica, 1984
- Influence of thyroid and growth hormone status on the rate of regulated Ca2+ efflux from rat liver mitochondriaBiochemical and Biophysical Research Communications, 1982
- Localization of 3,5,3′-L-triiodothyronine receptor in rat kidney mitochondrial membranesBiochemical and Biophysical Research Communications, 1982
- Binding of Thyroid Hormones in Serum and Liver Cytosol of Rana catesbeiana Tadpoles*Endocrinology, 1980
- Synergism of thyroid hormone and high carbohydrate diet in the induction of lipogenic enzymes in the rat. Mechanisms and implications.JCI Insight, 1980
- Hypothyroidism-Induced Changes in Triiodothyronine Binding to Nuclei and Cytosol-Binding Proteins in Rat Liver*Endocrinology, 1978
- Thyroglobulin Inhibition of Thyrotropin Binding to Thyroid Plasma Membrane*Journal of Clinical Endocrinology & Metabolism, 1978
- FACTORS INFLUENCING TRIIODOTHYRONINE BINDING PROPERTIES OF LIVER NUCLEAR RECEPTORSActa Endocrinologica, 1976
- A study of the conditions and mechanism of the diphenylamine reaction for the colorimetric estimation of deoxyribonucleic acidBiochemical Journal, 1956
- PROTEIN MEASUREMENT WITH THE FOLIN PHENOL REAGENTJournal of Biological Chemistry, 1951