Local BMP receptor activation at adherens junctions in the Drosophila germline stem cell niche
Local BMP receptor activation at adherens junctions in the Drosophila germline stem cell niche
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DOI：
10.1038/ncomms1426
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发表时间：
2011-08-01
影响因子：
16.6
通讯作者：
Boekel, Christian
中科院分区：
文献类型：
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作者：
Michel, Marcus;Raabe, Isabel;Boekel, Christian
根据哺乳动物造血系统的干细胞生态位突触假设，生态位信号的空间特异性是通过亚细胞限制信号传递到个体生态位和干细胞之间基于钙粘附素的连接而最大化的。然而，这样的突触从未被直接观察到，部分原因是没有工具来检测具有亚细胞分辨率的活性生长因子受体。在这里，我们描述了一种新的基于荧光的报告，它直接可视化骨形态发生蛋白(BMP)受体的激活，并表明在果蝇睾丸中，BMP利基信号优先在中枢干细胞和生殖系干细胞之间的贴壁连接处传递，类似于所提出的突触组织。配体分泌涉及外囊复合体和Rap激活剂Gef26，两者也是钙粘连蛋白向黏附连接运输所必需的。因此，我们建议本地产生BMP信号，通过共用卡粘素运输机械来实现。
According to the stem cell niche synapse hypothesis postulated for the mammalian haematopoietic system, spatial specificity of niche signals is maximized by subcellularly restricting signalling to cadherin-based adherens junctions between individual niche and stem cells. However, such a synapse has never been observed directly, in part, because tools to detect active growth factor receptors with subcellular resolution were not available. Here we describe a novel fluorescence-based reporter that directly visualizes bone morphogenetic protein (BMP) receptor activation and show that in the Drosophila testis a BMP niche signal is transmitted preferentially at adherens junctions between hub and germline stem cells, resembling the proposed synapse organization. Ligand secretion involves the exocyst complex and the Rap activator Gef26, both of which are also required for Cadherin trafficking towards adherens junctions. We, therefore, propose that local generation of the BMP signal is achieved through shared use of the Cadherin transport machinery.