Multiple positive and negative elements involved in the regulation of expression of GSY1 in Saccharomyces cerevisiae.
GSY1 is one of the two genes encoding glycogen synthase in Saccharomyces cerevisiae. Both the GSY1 message and the protein levels increased as cells approached stationary phase. A combination of deletion analysis and site-directed mutagenesis revealed a complex promoter containing multiple positive and negative regulatory elements. Expression of GSY1 was dependent upon the presence of a TATA box and two stress response elements (STREs). Expression was repressed by Mig1, which mediates responses to glucose, and Rox1, which mediates responses to oxygen. Characterization of the GSY1 promoter also revealed a novel negative element. This element, N1, can repress expression driven by either an STRE or a heterologous element, the UAS of CYC1. Repression by N1 is dependent on the number of these elements that are present, but is independent of their orientation. N1 repressed expression when placed either upstream or downstream of the UAS, although the latter position is more effective. Gel shift analysis detected a factor that appears to bind to the N1 element. The complexity of the GSY1 promoter, which includes two STREs and three distinct negative elements, was surprising. This complexity may allow GSY1 to respond to a wide range of environmental stresses.
Unnikrishnan
Indira
I
Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Miller
Steven
S
Meinke
Marilyn
M
LaPorte
David C
DC
D001483:Base Sequence; D004271:DNA, Fungal / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D006006:Glycogen Synthase / Q000235:genetics*; D016297:Mutagenesis, Site-Directed; D011401:Promoter Regions, Genetic; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D017384:Sequence Deletion; D014157:Transcription Factors / Q000235:genetics
D004271:DNA, Fungal; D004268:DNA-Binding Proteins; C085976:MIG1 protein, S cerevisiae; C081935:MSN2 protein, S cerevisiae; C081937:MSN4 protein, S cerevisiae; D012331:RNA, Fungal; D012333:RNA, Messenger; C083348:ROX1 protein, S cerevisiae; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D006006:Glycogen Synthase