UMMS Affiliation

Program in Gene Function and Expression; Program in Molecular Medicine

Date

2-7-2012

Document Type

Article

Medical Subject Headings

Binding Sites; Biological Assay; DNA, Fungal; DNA-Binding Proteins; Fluorescence; Galactokinase; Galactose; Gene Expression Regulation, Fungal; Histone Acetyltransferases; Mutation; Promoter Regions, Genetic; Protein Binding; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Trans-Activators; Transcription Factors; Transcriptional Activation

Disciplines

Genetics and Genomics

Abstract

Promoter-specific transcriptional activators (activators) stimulate transcription through direct interactions with one or more components of the transcription machinery, termed the "target." The identification of direct in vivo targets of activators has been a major challenge. Previous studies have provided evidence that the Tra1 subunit of the yeast SAGA (Spt-Ada-Gcn5-acetyltransferase) complex is the target of the yeast activator Gal4. However, several other general transcription factors, in particular the mediator complex, have also been implicated as Gal4 targets. Here we perform a large-scale genetic screen to derive and characterize tra1 alleles that are selectively defective for interaction with Gal4 in vivo [Gal4 interaction defective (GID) mutants]. In contrast to WT Tra1, Tra1 GID mutants are not recruited by Gal4 to the promoter and cannot support Gal4-directed transcription, demonstrating the essentiality of the Gal4-Tra1 interaction. In yeast strains expressing a Tra1 GID mutant, binding of Gal4 to the promoter is unexpectedly also diminished, indicating that Gal4 and Tra1 bind cooperatively. Consistent with cooperative binding, we demonstrate that the Gal4-Tra1 interaction occurs predominantly on the promoter and not off DNA. Finally, we show that although Tra1 is targeted by other activators, these interactions are unaffected by GID mutations, revealing an unanticipated specificity of the Gal4-Tra1 interaction.

Rights and Permissions

Citation: Ling Lin, Lynn Chamberlain, Lihua J. Zhu, and Michael R. Green. Analysis of Gal4-directed transcription activation using Tra1 mutants selectively defective for interaction with Gal4. Proc Natl Acad Sci U S A. 2012 Feb 7;109(6):1997-2002. Epub 2012 Jan 23. Link to article on publisher's site

Comments

Publisher PDF posted as allowed by the publisher's author rights policy, http://www.pnas.org/site/misc/authorfaq.shtml.

Related Resources

Link to Article in PubMed

PubMed ID

22308403

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.