Umeda P K, Darling D S, Kennedy J M, Jakovcic S, Zak R
Am J Cardiol. 1987 Jan 23;59(2):49A-55A. doi: 10.1016/0002-9149(87)90176-7.
The control of myosin expression by thyroid hormone is analyzed as an example of compensatory mechanisms of the heart. Two topics are discussed in detail: polymorphism of cardiac myosin heavy chains in the mammalian heart, and effect of thyroid hormone on myosin heavy chain expression by thyroid hormone. Our current knowledge about the identity of heavy chains and their corresponding isomyosins myosins is summarized and the dynamic nature of the myosin phenotype of the heart is discussed. The data on the thyroid hormone's role include studies in which the synthesis rate of the 2 classes of heavy chains (alpha and beta) was compared with their respective messenger RNA levels. A close correlation was observed and is consistent with pretranslational control. Transcription of myosin heavy chain genes was examined using isolated nuclei in a run-off experiment The rate of gene transcription was found to be the principal determinant of the cytoplasmic level of messenger RNA and of the isomyosin composition of the heart.
作为心脏代偿机制的一个例子，分析了甲状腺激素对肌球蛋白表达的控制。详细讨论了两个主题：哺乳动物心脏中心肌肌球蛋白重链的多态性，以及甲状腺激素对甲状腺激素介导的肌球蛋白重链表达的影响。总结了我们目前关于重链及其相应同工型肌球蛋白身份的知识，并讨论了心脏肌球蛋白表型的动态性质。关于甲状腺激素作用的数据包括比较两类重链（α和β）的合成速率与其各自信使RNA水平的研究。观察到密切相关性，这与转录前控制一致。在一项连续实验中，使用分离的细胞核检查了肌球蛋白重链基因的转录。发现基因转录速率是信使RNA细胞质水平和心脏同工型肌球蛋白组成的主要决定因素。
