New eukaryotic transcriptional repressors.
Transcriptional activating sequences have been described that are encoded by parts of the genome of Escherichia coli. These acidic peptides, fused to a DNA-binding fragment of the yeast transcriptional activator GAL4, activate transcription of a gene in a wide array of eukaryotes, provided that gene bears GAL4-binding sites nearby. Here we describe an E. coli-encoded sequence that, when attached to the same DNA-binding fragment (GAL4(1-147)), converts that fragment into a repressor. Thus, as assayed in yeast or in vitro in yeast extracts, this molecule represses transcription when bound upstream of a variety of different activators. Two additional repressing regions that work when tethered upstream, a multiple mutant derivative of the original isolate and a synthetic peptide are, like the original isolate, highly basic. At least one activator can be inhibited by the mutant but not by the parental repressing region. These and other findings suggest that these repressing regions interact with and inhibit the activity of activating regions bound nearby on DNA.
Saha
S
S
Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138.
Brickman
J M
JM
Lehming
N
N
Ptashne
M
M
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D011485:Protein Binding; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C064255:GAL4 (1-147) protein, S cerevisiae; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors