In:
Journal of Endocrinology, Bioscientifica, Vol. 99, No. 2 ( 1983-11), p. 251-260
Abstract:
A protein which shared several characteristics with authentic calmodulin was extracted from human thyroid homogenates. The protein bound to fluphenazine–Sepharose and could be specifically eluted using EGTA. The eluted protein had a u.v. spectrum characteristic of calmodulin and migrated like authentic calmodulin with a calcium-dependent shift on sodium dodecyl sulphate polyacrylamide-gel electrophoresis. Calmodulin in thyroid cell extracts was shown to be biologically active, measured by its ability to activate a calmodulin-deficient cyclic GMP phosphodiesterase; this activation could be inhibited by trifluoperazine. A possible role for calmodulin in the action of TSH on the thyroid was demonstrated by studying the effects of phenothiazines and the naphthalene sulphonamide, W7, a more specific calmodulin inhibitor, on TSH-stimulated cyclic AMP levels in cultured thyroid cells. The phenothiazines and W7 were found to inhibit the accumulation of cyclic AMP in response to TSH in a concentration-dependent manner although low concentrations of W7 enhanced TSH-stimulated cyclic AMP accumulation.
Type of Medium:
Online Resource
ISSN:
0022-0795
,
1479-6805
DOI:
10.1677/joe.0.0990251
Language:
Unknown
Publisher:
Bioscientifica
Publication Date:
1983
detail.hit.zdb_id:
1474892-7
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