Chang J P, Johnson J D, Van Goor F, Wong C J, Yunker W K, Uretsky A D, Taylor D, Jobin R M, Wong A O, Goldberg J I
Department of Biological Sciences, University of Alberta, Edmonton, Canada.
Biochem Cell Biol. 2000;78(3):139-53.
The intracellular signal transduction mechanisms mediating maturational gonadotropin and somatotropin secretion in goldfish are reviewed. Several major signaling mechanisms, including changes in intracellular [Ca2+], arachidonic acid cascades, protein kinase C, cyclic AMP/protein kinase A, calmodulin, nitric oxide, and Na+/H+ antiport, are functional in both cell types. However, their relative importance in mediating basal secretion and neuroendocrine-factor-regulated hormone release differs according to cell type. Similarly, agonist- and cell-type-specificity are also present in the transduction pathways leading to neuroendocrine factor-modulated maturational gonadotropin and somatotropin release. Specificity is present not only in the actions of different regulators within the same cell type and with the same ligand in the two cell types, but this also exists between isoforms of the same neuroendocrine factor within a single cell type. Other evidence suggests that function-selectivity of signaling may also result from differential modulation of Ca2+ fluxes from different sources. The interaction of different second messenger systems provide the basis by which regulation of maturational gonadotropin and somatotropin release by multiple neuroendocrine factors can be integrated at the target cell level.
本文综述了介导金鱼成熟促性腺激素和生长激素分泌的细胞内信号转导机制。几种主要的信号转导机制，包括细胞内[Ca2+]变化、花生四烯酸级联反应、蛋白激酶C、环磷酸腺苷/蛋白激酶A、钙调蛋白、一氧化氮和Na+/H+反向转运体，在这两种细胞类型中均起作用。然而，它们在介导基础分泌和神经内分泌因子调节的激素释放中的相对重要性因细胞类型而异。同样，在导致神经内分泌因子调节的成熟促性腺激素和生长激素释放的转导途径中也存在激动剂和细胞类型特异性。特异性不仅存在于同一细胞类型内不同调节因子的作用以及两种细胞类型中相同配体的作用中，而且也存在于单一细胞类型内同一神经内分泌因子的不同亚型之间。其他证据表明，信号转导的功能选择性也可能源于不同来源Ca2+通量的差异调节。不同第二信使系统的相互作用为多种神经内分泌因子对成熟促性腺激素和生长激素释放的调节在靶细胞水平上的整合提供了基础。
