Geisow M J, Burgoyne R D
Ann N Y Acad Sci. 1987;493:563-76. doi: 10.1111/j.1749-6632.1987.tb27241.x.
Pharmacological and morphological studies of secretion from bovine chromaffin cells indicate that the nicotinic receptor initiates intracellular signaling. An increase in [Ca2+]i is a necessary but not sufficient element for secretion. Receptor-dependent, but intracellular-Ca2+-independent alterations of the organization of cortical zone allows close approach of chromaffin granules and plasma membrane. Chromaffin granules possess both Ca2+-dependent and Ca2+-independent protein kinases, but the major substrates for these kinases appear to be associated with other organelles or to be soluble cytosolic proteins. Quantitatively the most important Ca2+-dependent cytosolic components that interact with the chromaffin granule do not show strict specificity for this secretory organelle, but are widely distributed in different cell types and are localized at or close to the plasma membrane in intact chromaffin and other cells. These molecules are closely related in biochemical properties and sequence and include substrates for membrane-associated kinases. Two of these proteins (caldesmon and p36) have binding sites for F-actin; the others described have binding sites for acidic phospholipids.
对牛嗜铬细胞分泌的药理学和形态学研究表明，烟碱样受体启动细胞内信号传导。细胞内钙离子浓度（[Ca2+]i）升高是分泌的必要但不充分条件。皮质区组织的受体依赖性但细胞内钙离子非依赖性改变允许嗜铬颗粒与质膜紧密靠近。嗜铬颗粒同时拥有钙离子依赖性和非依赖性蛋白激酶，但这些激酶的主要底物似乎与其他细胞器相关或为可溶性胞质蛋白。在数量上，与嗜铬颗粒相互作用的最重要的钙离子依赖性胞质成分对这种分泌细胞器没有严格的特异性，而是广泛分布于不同细胞类型中，并定位于完整嗜铬细胞和其他细胞的质膜处或附近。这些分子在生化特性和序列上密切相关，包括膜相关激酶的底物。其中两种蛋白质（钙调蛋白和p36）具有与F-肌动蛋白的结合位点；所述的其他蛋白质具有与酸性磷脂的结合位点。
