Calcium uptake via endocytosis with rapid release from acidifying endosomes
Calcium uptake via endocytosis with rapid release from acidifying endosomes
复制标题
DOI：
10.1016/s0960-9822(07)00565-9
复制
发表时间：
1998-12-03
期刊：
影响因子：
9.2
通讯作者：
Gerasimenko, OV
中科院分区：
文献类型：
--
作者：
Gerasimenko, JV;Tepikin, AV;Gerasimenko, OV
在许多不同的细胞类型中，已经描述了许多特定的细胞Ca2+摄取途径[1-3]。尽管已经认识到核内体可以储存Ca2+，但通过内吞作用输入大量Ca2+的可能性基本上被忽视了[4,5]。外分泌细胞可以通过胞吐释放大量的Ca2+，因此我们研究了Ca2+通过内吞作用进入内体的命运。Ca2+敏感和H+敏感荧光探针被放置在细胞外溶液中，随后通过内吞作用进入成纤维细胞。用共聚焦显微镜观察荧光强度的分布。内吞作用吸收的Ca2+在几分钟内从内体中消失，与内体酸化发生的时间相同。酸化通过降低细胞外Ca2+浓度来抑制，Ca2+从核内体的损失被巴菲霉素（100 nM）阻断，巴菲霉素是一种空泡质子atp酶的特异性抑制剂。定量评价表明，由于早期内体的快速损失，内吞作用导致大量Ca2+的输入。(C) Current Biology Ltd . ISSN 0960-9822。
A number of specific cellular Ca2+ uptake pathways have been described in many different cell types [1-3], The possibility that substantial quantities of Ca2+ could be imported via endocytosis has essentially been ignored, although it has been recognized that endosomes can store Ca2+ [4,5]. Exocrine cells can release significant amounts of Ca2+ via exocytosis [6], so we have investigated the fate of Ca2+ taken up via endocytosis into endosomes. Ca2+-sensitive and H+-sensitive fluorescent probes were placed in the extracellular solution and subsequently taken up into fibroblasts by endocytosis. Confocal microscopy was used to assess the distribution of fluorescence intensity. Ca2+ taken up by endocytosis was lost from the endosomes within a few minutes, over the same period as endosomal acidification took place. The acidification was inhibited by reducing the extracellular Ca2+ concentration, and Ca2+ loss from the endosomes was blocked by bafilomycin (100 nM), a specific inhibitor of the vacuolar proton ATPase. Quantitative evaluation indicated that endocytosis causes substantial import of Ca2+ because of rapid loss from early endosomes. (C) Current Biology Ltd ISSN 0960-9822.