Rapid inactivation of ovalbumin messenger ribonucleic acid after acute withdrawal of estrogen

Abstract

Synthesis of ovalbumin mRNA is induced and maintained in the avian oviduct by estrogen. When estrogen is rapidly removed from circulation, there is a general involution of the oviduct and an unusually rapid decay of ovalbumin mRNA activity. The kinetics of ovalbumin mRNA decay were not first order; instead, the rate of degradation increased about 10-fold over a 20-hr period after removal of estrogen. These results are in contrast with first-order decay kinetics observed for ovalbumin mRNA in estrogen-stimulated chicks (t(1/2) = about 24 hr) and in cell-free extracts. The degradative response triggered by hormonal withdrawal becomes more rapid between 1 and 4 days of estrogen-stimulated growth. We conclude that in the process of inducing egg-white protein synthesis, estrogen produces a cellular environment in which the egg-white protein mRNAs are relatively stable; removal of estrogen initiates cellular catabolism in a manner that is not understood.