The extended promoter of the gene encoding ribosomal protein S33 in yeast consists of multiple protein binding elements.
At least 4 different, protein binding cis-acting elements are present in the upstream region of the S33-gene. The major protein binding site is situated between positions -148 and -163 relative to the ATG start codon. It binds a trans-acting factor designated SUF (S33 Upstream Factor). When yeast cells are growing on glucose, deletion of this site results in a decrease of transcription of 50%. Using ethanol as a carbon-source, deletion of the SUF-responsive site lowers the transcription as much as 80%. A second protein binding site is found between positions -85 and -105. Only extracts from glucose-grown cells contain a factor that is able to bind to this site in vitro. A third protein binding site was found using a protein extract from ethanol-grown cells. This site, which is located quite close to the transcriptional start site, is probably responsible for the 20% residual transcription when the SUF binding site is removed. Finally, a site far upstream was found, which binds a protein from both glucose-grown and ethanol-grown cells. This site may function as an upstream repression site which is only functional when a non-fermentable carbon-source is used. Taking these findings into account, we present a model for the carbon-source dependent transcription activation of the gene encoding S33.
Herruer
M H
MH
Biochemisch Laboratorium, Vrije Universiteit, Amsterdam, The Netherlands.
Mager
W H
WH
Doorenbosch
T M
TM
Wessels
P L
PL
Wassenaar
T M
TM
Planta
R J
RJ
D001483:Base Sequence; D001665:Binding Sites; D002244:Carbon / Q000378:metabolism; D002874:Chromosome Mapping; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000502:physiology; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D015345:Oligonucleotide Probes; D011401:Promoter Regions, Genetic; D012269:Ribosomal Proteins / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014157:Transcription Factors / Q000502:physiology; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D015345:Oligonucleotide Probes; D012269:Ribosomal Proteins; D014157:Transcription Factors; C039982:ribosomal protein S33; D002244:Carbon