Regulation of functional mRNA levels for trypsin-like esteroproteases by 5 alpha-dihydrotestosterone and triiodothyronine in mouse submandibular salivary gland.

The effects of 5 alpha-dihydrotestosterone and triiodothyronine on the levels of mRNA for trypsin-like esteroproteases in the submandibular glands of young female mice were examined using a translation system in a reticulocyte lysate. Immunoprecipitation of the trypsin-like esteroproteases synthesized in vitro gave almost the same isozyme profile as that of enzymes synthesized in vivo on isoelectric focusing in acrylamide gel containing 8 M urea. Although 5 alpha-dihydrotestosterone and triiodothyronine induced the enzyme activity 3-5 times, these hormones increased their functional mRNA levels only 45-70 per cent. These results suggest that there is little if any post-translational processing of esteroproteases and that hormones increase both the amount of mRNA and the efficacy of its translation.