Studies on the desensitization of the cyclic AMP response to thyrotropin in thyroid tissue

Abstract

These studies were undertaken to examine, in the thyroid, whether N protein is specifically ADP-rybosylated by TSH. In addition, the functional activity of the N protein, as well as of the adenylate cyclase catalytic unit (C) was tested in membranes from thyroid cells desensitized to TSH. The data obtained suggest that N protein ADP-ribosylation is not responsible for TSH desensitization, and help localize the 'defect' in TSH desensitization to TSH receptor (R) function, or to R-N interaction.