Transcriptional regulation of CRP1 in smooth muscle

血管平滑肌细胞是血管壁的重要组成部分，具有非同寻常的 适应能力。这些细胞表现出一系列取决于选择性利用的表型 转录程序。虽然平滑肌调节对于正常的血管功能是必不可少的， 他们的适应能力与血管闭塞疾病的病理呈负相关。 因此，控制基因转录导致结果表型的分子机制是 在生物学和临床上都是相关的。作为阐明控制流畅的关键功能的入门途径 肌肉转录，我们的研究重点是前体细胞的发育和分化为 成熟的平滑肌肉。差异化伴随着一组精确的 收缩所需的基因。通过确定的调控元件和相应的转录 人们认识到，因子在分化中起作用，它们是如何与传递选择性的信号相耦合的 基因表达还没有被很好地理解。我们假设细胞外信号，比如转化生长 β因子(TGF-IS)，使用细胞内途径和转录因子的不同组合来传递 这是一种肌肉限制性表达。转化生长因子-李已成为执政顺畅的主要候选人 肌细胞表型。这项提案的目的是为了利用特定于平滑肌肉的 表达富含半胱氨酸的蛋白1(CRP1)基因，以研究顺式作用元件，并反式 传递选择性转录活性的作用因子，以响应定义的信号事件。我们有 确定了CRP1基因的一个独特的调节区，该区域仅在动脉平滑中驱动表达 肌肉细胞。我们打算使用这一调控元件来表征必要的转录途径。 在分化的平滑肌细胞中CRP1基因的表达具有重要意义。具体目标是： 1)明确CRP1基因通过转化激活的转录机制 生长因子-β1(TOF-I^)。2)确定血清功能活性之间的关系 反应因子(SRF)，以及控制平滑肌基因表达的信号事件。3)至 明确确定靶向表达CRP1的Carg元件的必要性 诱变。这些研究意义重大，因为它们将超出转录分析的范围。 调节器，并确定介导反式激活的确切途径，以解决根本 关于平滑肌细胞表型表现的问题。

Vascular smooth muscle cells are a vital component of the blood vessel wall, possessing extraordinary adaptive abilities. These cells display a range of phenotypes that are dependent upon the selective utilization of transcriptional programs. While smooth muscle modulation is essential for normal blood vessel function, their adaptive abilities are adversely associated with the pathologies of vascular occlusion diseases. Consequently, the molecular mechanisms governing gene transcription leading to resultant phenotypes are both biologically and clinically relevant. As an inroad to elucidating critical features that control smooth muscle transcription, our studies are focused on the development and differentiation of precursor cells into mature smooth muscle. Differentiation is accompanied by the orchestrated activation of a precise set of genes required for contraction. Though definitive regulatory elements, and corresponding transcription factors are recognized to have a role in differentiation, how they are coupled to signals that convey selective gene expression is not well understood. We hypothesize that extracellular signals, like transforming growth factor-beta (TGF-IS), use a distinct combination of intracellular pathways and transcription factors to impart smooth muscle-restricted expression. TGF-li has emerged as primary candidate for governing smooth muscle cell phenotypes. The aims of this proposal are designed to employ the smooth muscle-specific expression of the cysteine-rich protein 1 (CRP1) gene to investigate the cis-acting elements, and trans- acting factors that convey selective transcriptional activity in response to defined signaling events. We have identified a unique regulatory region of the CRP1 gene that drives expression exclusively in arterial smooth muscle cells. We intend to use this regulatory element to characterize essential transcriptional pathways important for the expression of the CRP1 gene in differentiated smooth muscle cells. The specific aims are: 1) To define the transcriptional mechanisms underlying the activation of the CRP1 gene by transforming growth factor-beta-1 (TOF-I^). 2) To determine the relationship between the functional activity of serum response factor (SRF), and signaling events that govern smooth muscle gene expression. 3) To unequivocally determine the necessity of the CArG element for expression of CRP1 by targeted mutagenesis. These studies are significant, as they will extend beyond the analysis of the transcriptional regulators, and determine the exact pathways that mediate transactivation, to address fundamental questions regarding the manifestation of smooth muscle cell phenotypes.