TSH regulates a gene expression encoding ERp29, an endoplasmic reticulum stress protein, in the thyrocytes of FRTL-5 cells

This experiment was performed to evaluate the effect of thyroid-stimulating hormone (TSH) on the endoplasmic reticulum resident 29 kDa protein (ERp29) gene expression in the thyrocytes of FRTL-5 cells. Although ERp29 mRNA was constantly expressed, its expression began to increase remarkably from 10( -9) M TSH. On the other hand, the effect of TSH on the abundance of ERp29 m RNA started within 6 h and peaked at 8 h. Actinomycin D strongly blocked th is effect while cycloheximide did not. The half-life of ERp29 mRNA was abou t 4-4.5 h in the presence or absence of TSH that was not affected by the st ability of ERp29 mRNA. The effect of TSH on the ERp29 gene expression was s pecific, while other growth factors (transferrin, insulin and hydrocortison e) did not alter its expression. Our data indicate for the first time that the expression of ERp29 is regulated transcriptionally by TSH in thyrocytes . (C) 2000 Federation of European Biochemical Societies. Published by Elsev ier Science B.V. All rights reserved.