GSBS Student Publications

Student Author(s)

Caroline S. Dacwag

Publication Date

2005-05-05

UMMS Affiliation

Department of Cell Biology

Document Type

Article

Disciplines

Cell Biology | Life Sciences | Medicine and Health Sciences

Abstract

The activation of muscle-specific gene expression requires the coordinated action of muscle regulatory proteins and chromatin-remodeling enzymes. Microarray analysis performed in the presence or absence of a dominant-negative BRG1 ATPase demonstrated that approximately one-third of MyoD-induced genes were highly dependent on SWI/SNF enzymes. To understand the mechanism of activation, we performed chromatin immunoprecipitations analyzing the myogenin promoter. We found that H4 hyperacetylation preceded Brg1 binding in a MyoD-dependent manner but that MyoD binding occurred subsequent to H4 modification and Brg1 interaction. In the absence of functional SWI/SNF enzymes, muscle regulatory proteins did not bind to the myogenin promoter, thereby providing evidence for SWI/SNF-dependent activator binding. We observed that the homeodomain factor Pbx1, which cooperates with MyoD to stimulate myogenin expression, is constitutively bound to the myogenin promoter in a SWI/SNF-independent manner, suggesting a two-step mechanism in which MyoD initially interacts indirectly with the myogenin promoter and attracts chromatin-remodeling enzymes, which then facilitate direct binding by MyoD and other regulatory proteins.

DOI of Published Version

10.1128/MCB.25.10.3997-4009.2005

Source

Mol Cell Biol. 2005 May;25(10):3997-4009. Link to article on publisher's site

Journal/Book/Conference Title

Molecular and cellular biology

Related Resources

Link to article in PubMed

PubMed ID

15870273

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