Endocrine secretory granules and neuronal synaptic vesicles have three integral membrane proteins in common.
Endocrine secretory granules and neuronal synaptic vesicles have three integral membrane proteins in common.
复制标题
DOI：
10.1083/jcb.106.1.51
复制
发表时间：
1988-01
期刊：
影响因子：
--
通讯作者：
Kelly RB
中科院分区：
文献类型：
--
作者：
Lowe AW;Madeddu L;Kelly RB
在对外界刺激的反应中，神经元细胞从小突触囊泡释放神经递质，内分泌细胞从大的致密核心颗粒释放分泌蛋白。尽管存在这些差异，内分泌细胞表达三种已知是突触囊泡膜组分的蛋白质。为了确定是否所有三种蛋白质，p38，p65，和SV2，存在于内分泌致密的核心颗粒膜，结合珠的单克隆抗体被用来免疫分离细胞器含有突触囊泡抗原。[3H]去甲肾上腺素被用来标记从牛肾上腺髓质和大鼠嗜铬细胞瘤（PC 12）细胞纯化的嗜铬颗粒。从标记的纯化牛嗜铬颗粒和PC12核后上清液中免疫分离出高达80%的囊泡[3H]去甲肾上腺素。在用编码人生长激素的DNA转染的PC12细胞中，该激素被包装并与去甲肾上腺素一起释放。90%的可沉淀激素也被所有三种蛋白质的抗体免疫分离。刺激分泌的PC12细胞通过去极化与50 mM KCl的量减少[3H]去甲肾上腺素或人生长激素免疫分离。免疫分离组分的电子显微镜检查显示大的（直径大于100 nm）致密的核心囊泡粘附到珠。因此，含有分泌蛋白的大而致密的核心囊泡具有所有三种已知的突触囊泡膜蛋白。
In response to an external stimulus, neuronal cells release neurotransmitters from small synaptic vesicles and endocrine cells release secretory proteins from large dense core granules. Despite these differences, endocrine cells express three proteins known to be components of synaptic vesicle membranes. To determine if all three proteins, p38, p65, and SV2, are present in endocrine dense core granule membranes, monoclonal antibodies bound to beads were used to immunoisolate organelles containing the synaptic vesicle antigens. [3H]norepinephrine was used to label both chromaffin granules purified from the bovine adrenal medulla and rat pheochromocytoma (PC12) cells. Up to 80% of the vesicular [3H]norepinephrine was immunoisolated from both labeled purified bovine chromaffin granules and PC12 postnuclear supernatants. In PC12 cells transfected with DNA encoding human growth hormone, the hormone was packaged and released with norepinephrine. 90% of the sedimentable hormone was also immunoisolated by antibodies to all three proteins. Stimulated secretion of PC12 cells via depolarization with 50 mM KCl decreased the amount of [3H]norepinephrine or human growth hormone immunoisolated. Electron microscopy of the immunoisolated fractions revealed large (greater than 100 nm diameter) dense core vesicles adherent to the beads. Thus, large dense core vesicles containing secretory proteins possess all three of the known synaptic vesicle membrane proteins.