Hsp27 Association with Contractile Proteins

描述（申请人摘要）：本项目的目标是 了解HSP 27在正常生理机制中的作用， 结肠平滑肌收缩。调查员认为 结肠平滑肌细胞内的信号级联， HSP 27的磷酸化以及HSP 27与其他蛋白的结合， 收缩蛋白，特别是肌动蛋白、原肌球蛋白、肌球蛋白和钙调蛋白， 导致平滑肌收缩。这一级联反应由PKC启动 激活，通过PKC易位到膜，导致MAP激活 激酶。该假说认为，HSP 27在维持细胞凋亡中起着重要作用。 细胞骨架的完整性，以及细胞骨架之间的联系， 平滑肌细胞内的蛋白质。申请人的研究将决定如何 HSP 27的磷酸化赋予与收缩蛋白的结合， 导致收缩。新的数据表明，HSP 27的磷酸化 通过增加稳定性在细胞骨架重组中起作用， 平滑肌细胞中收缩蛋白的结合。HSP 27是 响应于不同的收缩激动剂如蛙皮素而磷酸化， 内皮素卡巴胆碱和神经酰胺。初步数据还表明， HSP 27的磷酸化伴随着HSP 27的复合增加。 HSP 27与肌动蛋白和原肌球蛋白。收缩也伴随着 HSP 27与肌动蛋白和原肌球蛋白的强共定位。舒张 神经肽VIP和PKC抑制剂calphostin C都能抑制 收缩和HSP 27磷酸化的抑制，表明 HSP 27的磷酸化和收缩可能相关。的具体目标 这一建议是：1）检查PKC介导的收缩的影响， HSP 27磷酸化和细胞骨架重组：2）检查 PKC介导的HSP 27与肌动蛋白的结合收缩，以及其他 收缩蛋白是平滑肌细胞收缩机制的成员， 肌肉，即肌球蛋白，钙调蛋白和原肌球蛋白;和3）检查 HSP 27与肌动蛋白，肌球蛋白， 钙调素和原肌球蛋白。

DESCRIPTION (Applicant's Abstract): The objective of this project is to understand the role of HSP27 in normal physiologic mechanisms that modulate smooth muscle contraction of the colon. The investigator propose the existence of an intracellular signaling cascade in colonic smooth muscle that results in the phosphorylation of HSP27 and the association of HSP27 with other contractile proteins, particularly actin, tropomyosin, myosin and caldesmon, leading to smooth muscle contraction. This cascade is initiated by PKC activation, by PKC translocation to the membrane, leading to activation of MAP kinases. The hypothesis is that HSP27 plays an important role in maintaining cytoskeletal integrity, and cytoskeletal association between the contractile proteins within smooth muscle cells. The applicant's studies will determine how phosphorylation of HSP27 confers association with the contractile proteins, leading to contraction. Emerging data suggest that phosphorylation of HSP27 plays a role in cytoskeletal reorganization by increasing stability and association of the contractile proteins in smooth muscle cells. HSP27 is phosphorylated in response to different contractile agonists like bombesin, endothelin, carbachol and ceramide. Preliminary data also suggest that phosphorylation of HSP27 is accompanied by an increase in the complexing of HSP27 with actin and with tropomyosin. Contraction is also accompanied with a strong colocalization of HSP27 with actin and with tropomyosin. The relaxant neuropeptide VIP and the PKC inhibitor calphostin C cause both an inhibition of contraction and an inhibition of HSP27 phosphorylation, suggesting that phosphorylation of HSP27 and contraction may be related. The specific aims of this proposal are to: 1) examine the effect of PKC mediated contraction on HSP27 phosphorylation and cytoskeletal reorganization: 2) examine the effect of PKC mediated contraction on the association of HSP27 with actin, and other contractile proteins that are members of the contractile machinery in smooth muscle, namely myosin, caldesmon, and tropomyosin; and 3) examine the effect of altered expression of HSP27 on the association of HSP27 with actin, myosin, caldesmon and tropomyosin in transfected cells and in transgenic mice.