TISSUE-SPECIFIC CONTROL OF MUSCLE GENE EXPRESSION

骨骼肌分化伴随着坐标 肌瘤蛋白的诱导。这些东西的出现 在蛋白质之前，蛋白质的丰度上升 相应的反映转录增加的mRNAs 活动。这种转录的增加，反过来又依赖于 正确的顺式和反式作用元件的存在。我们 最近在骨骼肌中发现了一种核因子， 与上游序列特异性和高亲和力结合 位于编码肌瘤蛋白的基因的5‘端的元件， A-肌动蛋白和肌球蛋白轻链2。这一发现支持 假设肌节蛋白是协同诱导的 通过有限数量的反式作用因子的作用。在……里面 在本申请中，我们建议扩展这些观察结果 通过(I)描绘上游特定肌肉的作用， 肌肉基因表达调控中的序列元件(II) 骨骼肌核因子的纯化与鉴定(S) 与该序列结合的序列(III)形成体外转录 严格评估监管职能的制度 肌肉特定因素。我们的目标是提纯反式作用 DNA结合序列的影响因素及其作用的阐明 在组织特异性基因调控中，是 了解最终导致的发展级联 在成肌细胞分化中的作用。

Skeletal muscle differentiation is accompanied by the coordinate induction of sarcomeric proteins. The appearance of these proteins is preceded by a rise in the abundance of the corresponding mRNAs reflecting an increase in transcriptional activity. This transcriptional increase, in turn, is dependent upon the presence of the correct cis- and trans- acting elements. We have recently identified a nuclear factor in skeletal muscle which binds specifically and with high affinity to an upstream sequence element located 5' to the genes encoding the sarcomeric proteins, a-actin and myosin light chain 2. This finding lends support to the hypothesis that the sarcomeric proteins are coordinately induced through the action of a limited number of trans-acting factors. In the present application, we propose to extend these observations by (i) Delineating the role of the upstream muscle specific, sequence element in the regulation muscle gene expression (ii) Purifying and characterizing the skeletal muscle nuclear factor(s) that bind to this sequence (iii) Developing an in vitro transcription system with which to rigorously assess the regulatory function of muscle specific factors. Our goal, the purification of trans-acting factors and the elucidation of the role of DNA binding sequences in tissue-specific gene regulation, is the first step in understanding the developmental cascade which eventually results in myoblast differentiation.