Huang W Y, Liew C C
Laboratory for Molecular Cardiology, Departments of Clinical Biochemistry and Medicine, University of Toronto, Toronto, Ontario, Canada M5G IL5.
Biochem J. 1997 Jul 1;325 ( Pt 1)(Pt 1):47-51. doi: 10.1042/bj3250047.
Transgenic analysis has indicated that far upstream regulatory elements of the cardiac alpha-myosin heavy chain (MyHC) gene are required for appropriate transgene expression [Subramaniam, Gulick, Neumann, Knotts and Robbins (1993) J. Biol. Chem. 268, 4331-4336]. In an attempt to identify these as-yet-undefined regulatory elements, we mapped the DNase I hypersensitive sites (DHSs) in the 4 kb upstream region of the hamster cardiac alpha-MyHC gene. When using nuclei isolated from late-gestational and adult heart ventricles, a strong DHS was identified in the -1.9 kb region (alpha-1.9 kb site). It cannot be detected in kidney, liver or cardiofibroblast nuclei. Within this site, we found a conserved GATA-motif that interacts specifically with GATA-binding factors in nuclear extracts of cardiomyocytes at various developmental stages. These data provide further evidence to support the role of GATA factors in the regulation of cardiac alpha-MyHC gene expression.
转基因分析表明，心脏α-肌球蛋白重链（MyHC）基因的远上游调控元件对于转基因的适当表达是必需的[Subramaniam、Gulick、Neumann、Knotts和Robbins（1993年）《生物化学杂志》268卷，4331 - 4336页]。为了鉴定这些尚未明确的调控元件，我们绘制了仓鼠心脏α-MyHC基因上游4 kb区域的脱氧核糖核酸酶I超敏位点（DHSs）图谱。当使用从妊娠后期和成年心脏心室分离的细胞核时，在-1.9 kb区域（α-1.9 kb位点）鉴定出一个强DHS。在肾脏、肝脏或心脏成纤维细胞核中无法检测到它。在该位点内，我们发现了一个保守的GATA基序，它在不同发育阶段的心肌细胞核提取物中与GATA结合因子特异性相互作用。这些数据为支持GATA因子在心脏α-MyHC基因表达调控中的作用提供了进一步的证据。
