To investigate the role of chromatin structure in cardiac gene expression, we used the DNase I and micrococcal nuclease to probe the chromatin structure of the hamster cardiac β-MyHC gene. Two cardiac-specific DNase I hypersensitive sites (DHS) were identified, one of which was mapped to the -2.3 kb (β-2.3 kb) region and the other to the proximal promoter region of the β-MyHC gene. The two sites were readily detectable using nuclei from neonatal hamster heart; however, the proximal promoter site disappeared when adult hamster heart nuclei were used, and the -2.3 kb site decreased in intensity. We were able to demonstrate the gradual disappearance of this proximal promoter DHS by comparing heart nuclei isolated from animals at late-gestation and 1-day-old stages. Furthermore, injecting thyroid hormone caused the disappearance of the proximal promoter DHS in late gestational fetal ventricular nuclei. Digestion of nuclei from various tissues by micrococcal nuclease revealed that the β-MyHC gene proximal promoter exists in an array of three specifically-positioned nucleosomes only in fetal heart chromatin. The β-MyHC gene proximal promoter is DNase I hypersensitive within one of the nucleosomal particles. Our data suggest that chromatin structure may participate actively in cardiac gene expression.
Skip Nav Destination
Research Article| March 01 1998
Chromatin remodelling of the cardiac β-myosin heavy chain gene
Weei-Yuarn HUANG ;
Choong-Chin LIEW 1
1Laboratory for Molecular Cardiology, Departments of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
1To whom correspondence should be addressed at: The Cardiac Gene Unit, 100 College Street, Banting Institute, Room 418, University of Toronto, Toronto, Ontario, M5G 1L5, Canada.
Search for other works by this author on:
- Views Icon Views
- Share Icon Share
Weei-Yuarn HUANG, Choong-Chin LIEW; Chromatin remodelling of the cardiac β-myosin heavy chain gene. Biochem J 1 March 1998; 330 (2): 871–876. doi: https://doi.org/10.1042/bj3300871
Download citation file:
Don't already have an account? Register
Get Access To This Article
Buy This Article