IDENTIFICATION OF CIS-ACTING AND TRANS-ACTING ELEMENTS INVOLVED IN THE EXPRESSION OF COLD SHOCK-INDUCIBLE TIP1 GENE OF YEAST SACCHAROMYCES-CEREVISIAE

Northern blot hybridization analysis of a series of 5' end, 3' end and internal deletions has revealed that at least four different regions are involved in the regulation of the expression of TIP1, a cold shock -inducible gene of Saccharomyces cerevisiae. One of these four regions has negative effect on the expression of the TIP1 gene, while the oth ers are responsible for the activation and cold shock-induction of the gene. A fragment involved in the cold-shock induction of TIP1 was use d as a probe in gel retardation assays to identify the cold shock-fact or. The cold shock-factor could be detected in cells grown at 30 degre es C as well as 10 degrees C, but both the amount of the factor and it s affinity to DNA were found to increase 2 - 3-fold after cold shock. In addition, another factor was found to bind just upstream of the col d shock element, in a region where a transcriptional activator was pre dicted to function by Northern blot hybridization analysis. The amount of this activating factor and its affinity for DNA was not affected b y temperature. Implications of our data on possible mechanisms of tran scriptional regulation of the TIP1 gene by cold shock are discussed.