MYOTONIC DYSTROPHY KINASE IN MYOCYTE DEVELOPMENT

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者的研究机构。 本研究的目的是确定人强直性肌营养不良蛋白激酶（DMPK）在肌细胞发育中的功能。DMPK最初是通过检测位于DMPK基因3 '非翻译区的CTG三联体重复序列来鉴定的，该序列在强直性肌营养不良（DM1）患者中扩增。在DM1的病理生理学中DMPK表达减少的作用不能确定，直到激酶的功能已被明确定义。我们的初步数据表明DMPK可能调节心肌细胞的发育。 当增殖细胞转变为有丝分裂后细胞时，DMPK在发育中的肌细胞中表达。HeLa细胞中的过表达研究表明DMPK足以破坏细胞周期。培养的小鼠成肌细胞（C2C12细胞）中DMPK的耗竭抑制分化为肌管并改变细胞形态。我们将测试DMPK在肌生成中起关键作用的新假设。DMPK是肌源性基因表达所需的，并且足以在成肌细胞中过早诱导肌源性基因表达。目的1将检验DMPK对于肌细胞分化是必需的并且足以诱导过早的肌细胞分化的假设。目的2将验证DMPK启动退出细胞周期的假设。目的3将验证DMPK是未成熟成肌细胞分化所必需的假设。总之，这些实验将导致对DMPK在肌细胞发育中的功能的理解，并将基于对DM1肌细胞病理生理学的完整理解为DM1的治疗奠定基础。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of the proposed study is to identify the function of human myotonic dystrophy protein kinase (DMPK) in myocyte development. DMPK was originally identified by the detection of a CTG triplet repeat sequence located in the 3' untranslated region of the DMPK gene that is expanded in patients with myotonic dystrophy (DM1). A role for the reduced DMPK expression in the pathophysiology of DM1 cannot be determined until the function of the kinase has been clearly defined. Our preliminary data suggests DMPK may regulate myocyte development. DMPK is expressed in developing myocytes when proliferating cells transition into postmitotic cells. Overexpression studies in HeLa cells demonstrate that DMPK is sufficient to disrupt the cell cycle. The depletion of DMPK in cultured mouse myoblasts (C2C12 cells) inhibits differentiation into myotubes and alters cell morphology. We will test the novel hypothesis that DMPK has a key role in myogenesis. DMPK is required for myogenic gene expression and is sufficient to prematurely induce myogenic gene expression in myoblasts. Aim 1 will test the hypothesis that DMPK is necessary for myocyte differentiation and is sufficient to induce premature myocyte differentiation. Aim 2 will test the hypothesis that DMPK initiates exit from the cell cycle. Aim 3 will test the hypothesis that DMPK is required for the differentiation of immature myoblasts. Together, these experiments will lead to an understanding of DMPK function in muscle cell development and will lay the groundwork for treatments for DM1 based on a complete understanding of DM1 myocyte pathophysiology.