MOLECULAR MECHANISMS REGULATING CALCIUM FLUX IN SALIVARY GLANDS

调节唾液腺钙通量的分子机制

• 批准号: 6432011
• 负责人: INDU S. AMBUDKAR
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DENTAL & CRANIOFACIAL RESEARCH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6432011
• 关键词: basolateral membrane; calcium channel; calcium flux; laboratory rat; parotid gland; potassium channel; salivary glands; submandibular gland; tissue /cell culture; voltage /patch clamp

Neurotransmitter stimulation of fluid secretion in salivary glands is mediated via a biphasic elevation in cytosolic [Ca-2+]; an initial transient increase due to internal release and a latter sustained increase due to Ca-2+ influx. Sustained fluid secretion is suggested to directly dependent upon the sustained elevation of [Ca-2+]and thus on Ca-2+ influx. This project is aimed towards understanding the mechanisms which mediate and regulate Ca-2+ signaling in salivary gland cells. Recently, our efforts have been focused on the mechanisms involved in mediating and regulating Ca-2+ influx into salivary gland cells. Ca-2+ influx in salivary cells is prototypical of the store-operated Ca-2+ influx mechanism present in many other non-excitable cells. The molecular mechanism(s) of this influx has not yet been determined in any cell type. Recently, the transient receptor potential (Trp)family of ion channel proteins have been proposed as molecular components of the store-operated Ca-2+ influx channel. We have previously reported cloning of rat Trp1 and identification and localization of the endogenous Trp1 protein in rat and human salivary gland cells. In this reporting period we have further studied the role of Trp1 in the store-operated Ca-2+ influx mechanism. Our studies suggest that Trp1 is a strong candidate for the Ca-2+ influx channel in salivary gland cells. Further, we have reported that Trp1 is localized in a lipid raft region where it is assembled in a larger signaplex along with other Ca-2+ signaling molecules, such as the IP3R and G-proteins. salivary glands and human salivary gland cell lines. We propose that protein-protein interactions facilitated within this signaplex regulate store-operated Ca-2+ influx. Results from our functional studies where we have examined the Ca-2+ current mediated by the store-operated Ca-2+ channel by using patch clamp methodology, are also consistent with these findings. Our future studies will continue to focus on the store-operated Ca-2+ influx pathway, its regulation and role in salivary gland fluid secretion.

唾液腺中液体分泌的神经递质刺激通过胞质[Ca-2+]的双相升高介导；由于内部释放而引起的初始瞬态增加，而后者由于Ca-2+涌入而持续增加。 建议持续的流体分泌直接取决于[Ca-2+]的持续升高，从而取决于Ca-2+流入。 该项目旨在理解唾液腺细胞中介导和调节Ca-2+信号传导的机制。最近，我们的努力集中在介导和调节Ca-2+流入唾液腺细胞中的机制上。唾液细胞中的Ca-2+流入是库存经营的Ca-2+涌入机制的典型型。在任何细胞类型中尚未确定这种流入的分子机制。最近，已经提出了离子通道蛋白的瞬时受体电位（TRP）家族作为储存的CA-2+涌入通道的分子成分。我们先前已经报道了大鼠TRP1的克隆以及大鼠和人唾液腺细胞中内源性TRP1蛋白的鉴定和定位。在此报告期间，我们进一步研究了TRP1在商店经营的CA-2+涌入机制中的作用。 我们的研究表明，TRP1是唾液腺细胞中Ca-2+涌入通道的有力候选者。此外，我们已经报道了TRP1位于脂质筏区域中，该区域将其与其他Ca-2+信号分子（例如IP3R和G蛋白）一起组装在较大的标准中。唾液腺和人类唾液腺细胞系。我们提出，在此标本中调节储存的Ca-2+流入中，蛋白质 - 蛋白质相互作用促进了。 我们功能研究的结果是，我们检查了使用斑块夹方法介导的Ca-2+电流，也与这些发现一致。我们未来的研究将继续关注储存的CA-2+涌入途径，其调节和在唾液腺液体分泌中的作用。