The two Saccharomyces cerevisiae SUA7 (TFIIB) transcripts differ at the 3 '-end and respond differently to stress

Despite much information as to the structure and function of the general tr anscription factors, little is known about the regulation of their expressi on, Transcription of the Saccharomyces cerevisiae SUA7 (TFIIB) gene results in the formation of two discrete transcripts. It was originally reported t hat the two transcripts were derived from two promoters separated by simila r to 80 bp, We have found that the two transcripts are instead derived from a common promoter and differ at the 3'-end by similar to 115 bp, The longe r of the two transcripts has an unusually long 3'-untranslated region. We h ave analyzed the levels of these transcripts under different cell growth co nditions and find that the relative amounts of the two transcripts vary. Ap proximately equal amounts of each transcript are observed during exponentia l growth, but stresses and growth limiting conditions lead to a decrease in the relative amount of the larger transcript. These results suggest that t he expression of the SUA7 gene may be controlled by regulation of 3'-end fo rmation or mRNA stability. One of the general transcription factors, then, may be subject to regulation by a general response of the mRNA processing m achinery.