The Endocrinology and Reproduction Research Branch, National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
Trends Endocrinol Metab. 1994 Aug;5(6):250-5. doi: 10.1016/1043-2760(94)p3084-k.
Numerous circulating and locally produced hormones bind to specific cell-surface receptors and activate a variety of second-messenger pathways that evoke characteristic phenotypic responses in their target cells. One of the most ubiquitous signal transduction mechanisms is the phosphoinositide-calcium messenger system, which is activated by hormones, neurotransmitters, and growth factors. Stimulation of these receptors by their ligands causes a characteristic change in the metabolism of membrane phospholipids with production of diacylglycerol and a rapid increase in cytoplasmic Ca(2+) concentration, due to the release of stored intracellular Ca(2+) and stimulated Ca(2+) entry from the extracellular space. These intracettular signals act in concert to activate protein kinases that phosphorylate a variety of regulatory proteins. The link between phosphoinositide turnover and Ca(2+) mobilization is inositol 1,4,5-trisphosphate, the major Ca(2+)-mobilizing second messenger, which is produced from membrane phosphoinositides by activated phospholipase C enzymes. The mechanisms of ligand-regulated Ca(2+) influx and the additional regulatory role(s) of phosphoinositides and inositol phosphates are still being unfolded. This review and the following article summarize some recent developments and unsolved issues about this major signal transduction cascade that links calcium-mobilizing hormone receptors to the regulation of endocrine cell function.
许多循环和局部产生的激素与特定的细胞表面受体结合，并激活各种第二信使途径，在其靶细胞中引发特征性表型反应。最普遍的信号转导机制之一是磷酸肌醇-钙信使系统，它被激素、神经递质和生长因子激活。其配体刺激这些受体，导致膜磷脂代谢的特征性变化，产生二酰甘油，并由于储存的细胞内 Ca(2+)释放和细胞外空间刺激的 Ca(2+)内流，细胞质 Ca(2+)浓度迅速增加。这些细胞内信号协同作用激活蛋白激酶，使各种调节蛋白磷酸化。磷酸肌醇周转率与 Ca(2+)动员之间的联系是肌醇 1,4,5-三磷酸，它是主要的 Ca(2+)动员第二信使，由激活的磷酯酶 C 酶从膜磷酸肌醇中产生。配体调节的 Ca(2+)内流的机制和磷酸肌醇和肌醇磷酸盐的额外调节作用仍在阐明中。这篇综述和以下文章总结了关于这个主要的信号转导级联的一些最新进展和未解决的问题，该级联将钙动员激素受体与内分泌细胞功能的调节联系起来。
