Molecular events associated with glucose repression of invertase in Saccharomyces cerevisiae.

When S. cerevisiae growing in the presence of glucose (repressive condition) was shifted to higher temperatures, invertase was secreted. This secretion required protein synthesis, but was independent of RNA formation (Mormeneo & Sentandreu 1982). In addition accumulation of invertasespecific messenger RNA occurred in the absence of protein synthesis but was expressed only after synthesis of protein. Invertase mRNA was continuously synthesized under repressive conditions and the levels of this mRNA were regulated by the presence of glucose. The hexose regulated the concentration of this mRNA at the level of transcription and/or by sensitization of this messenger RNA. The expression of the invertase mRNA present in the cells under repressive conditions was also regulated by glucose at the level of translation and/or secretion. As a result of these processes, under repressive conditions invertase is eliminated before secretion takes place.