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Negative regulation of transcription by the yeast global transcription factors, Gal11 and Sin4
Author(s) -
Nishizawa Masafumi
Publication year - 2001
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/yea.754
Subject(s) - biology , transcription (linguistics) , general transcription factor , transcription factor , genetics , rna polymerase ii , e box , yeast , gene , microbiology and biotechnology , promoter , gene expression , enhancer , philosophy , linguistics
Gal11 and Sin4 proteins are yeast global transcription factors that regulate transcription of a variety of genes, both positively and negatively. Gal11, in a major part, functions in the activation of transcription, whereas Sin4 has an opposite role, yet they are reported to be present as a complex in the so‐called RNA polymerase II holoenzyme. To reveal howthese auxiliary factors participate in switching transcription on and off, a complex formation between Gal11 and Sin4 and its effect on the negative regulation of transcription were studied. Using an artificial promoter that is negatively regulated by Gal11, it was shown that the presence of Sin4 or Pgd1/Hrs1/Med3 was required for Gal11 to repress both basal and activated transcription. Genetic and biochemical studies using a temperature‐sensitive Gal11 mutant showed that the amino acid region 866–910 essential for Gal11 function was also important for repression of transcription and a complex formation with Sin4. Analysis with dam methylase accessibility to the promoter region suggested that nucleosome structure may be involved in negative regulation. Based on these results, possible mechanisms by which a mediator subcomplex regulates transcription is discussed. Copyright © 2001 John Wiley & Sons, Ltd.