Induction of brain tubulin by triidothyronine: dual effect of the hormone on the synthesis and turnover of the protein

Abstract

The relative effects of triiodothyronine (T₃) on the synthesis and turnover of tubulin in the developing rat and chick brain have been examined. Measurements of rates of turnover of radiolabeled tubulin in the hormone-sensitive tissues show that the half-life of tubulin turnover is 4-6 h in the absence of T₃ and 10-12 h in the presence of the hormone. Analysis of short-term kinetic data on the stimulation of tubulin by T₃ in the chick brain show that the rapid induction is due to a dual effect of the hormone on the metabolism of tubulin -an increase in the rate of synthesis as well as a decline in its rate of turnover.