DEVELOPMENTAL REGULATION OF HUMAN MUSCLE PROTEINS

在人类发育过程中， 肌肉变化的收缩器。 因此，不同 由多基因家族成员编码的蛋白质存在于 肌肉在胚胎、新生儿和成人发育阶段。 肌肉蛋白质异构体的变化发生在细胞分裂的过程中， 分化、个体发育和对生理刺激的反应 这些变化对收缩性 肌肉的特性。 复杂的监管机制必须 存在决定正确的蛋白质在细胞中表达的基因。 在正确的时间正确的地点。 肌肉发育过程中基因表达的可塑性是 特别是在数量和多样性方面， 肌球蛋白重链蛋白（肌球蛋白）。 的一大进步 在培养物中表达人肌球蛋白的研究 使用荧光激活细胞分选仪。 现在，纯 原代人肌细胞群可以在 在人类发育的各个阶段， 在文化上有所区别。 此外，人的调节 肌球蛋白基因表达可以在异核体、细胞 融合产物，其中休眠的人类肌肉基因被 激活 一个发展的过程中的表达 最近在培养的细胞中检测到了几种肌球蛋白基因， 用单克隆抗体检测人肌细胞，高度敏感 和识别不同人类肌球蛋白的特异性试剂。 这些肌肉基因表达的转变现在可以通过 生化和分子分析 这一建议的具体目的是增加我们的理解 人类肌肉蛋白质的发育调节。 为此，在体内表达的人肌球蛋白的序列 将在体外表征和诱导。 发育 肌球蛋白基因表达的调控 将在异核体中探索反式作用因子。 的 特异于发育和纤维类型特异性肌球蛋白的cDNA 其表达已经用单克隆抗体分析 将被分离并鉴定。 这种方法应该 最终导致对监管、结构和 肌球蛋白重链基因家族成员的功能， 在人类发展过程中的分子水平。

During human development the structural components of the contractile apparatus of muscle change. Accordingly, distinct proteins encoded by members of multigene families are present in muscle at embryonic, neonatal and adult stages of development. Changes in muscle protein isoforms occur in the course of cell differentiation, ontogeny, and in response physiological stimuli and these changes have a marked impact on the contractile properties of the muscle. Complex regulatory mechanisms must exist that determine that the correct protein is expressed in the correct place at the correct time. The plasticity of gene expression during muscle development is especially well demonstrated by the number and diversity of myosin heavy chain proteins (myosins). A major advance in the study of the expression of human myosins in culture has resulted from the use of the fluorescence-activated cell sorter. Now, pure populations of primary human muscle cells can be isolated in quantity from muscle tissues at all stages of human development and differentiated in culture. In addition, the regulation of human myosin gene expression can be monitored in heterokaryons, cell fusion products in which dormant human muscle genes are activated. A developmental progression in the expression of several myosin genes has recently been detected in cultured human muscle cells with monoclonal antibodies, highly sensitive and specific reagents that recognize distinct human myosins. These transitions in muscle gene expression are now amenable to a biochemical and molecular analysis. The specific aim of this proposal is to increase our understanding of the developmental regulation of human muscle proteins. Toward this end, the sequence of human myosins expressed in vivo will be characterized and induced in vitro. The developmental regulation of myosin gene expression by putative stage-specific trans-acting factors will be explored in heterokaryons. The cDNAs specific to developmental and fiber-type specific myosins whose expression has been analyzed with monoclonal antibodies will be isolated and characterized. This approach should ultimately lead to the dissection of the regulation, structure and function of members of the myosin heavy chain gene family at a molecular level in the course of human development.