Endosome fusion and microtubule-based dynamics in the early endocytic pathway of Dictyostelium
Endosome fusion and microtubule-based dynamics in the early endocytic pathway of Dictyostelium
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DOI：
10.1034/j.1600-0854.2002.31104.x
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发表时间：
2002-11-01
期刊：
影响因子：
4.5
通讯作者：
Gerisch, G
中科院分区：
文献类型：
--
作者：
Clarke, M;Köhler, J;Gerisch, G
与哺乳动物巨噬细胞一样，变形虫盘基骨柱通过巨噬作用吸收液体。本研究使用荧光液相标记物和gfp标记的微管来观察盘基骨菌早期核内体的摄取、动力学和融合。用两种荧光液相标记物连续标记表明，在摄取后的最初几分钟内，新的巨肽小体与原有的内体融合。融合的核内体，代表混合室，表现出极端的形状变化和与微管相关的细胞快速运输。电子显微镜也显示出成熟阶段核内体的巨大可塑性。微管的持续波动运动有助于与核内体建立接触。用选择性破坏肌动蛋白丝或微管的药物治疗细胞，证实了内核体动力学是以微管为基础的。核内体的进一步成熟导致多形性丧失，有利于球形，无法与新的大小体融合，运动能力下降。
Dictyostelium amoebae, like mammalian macrophages, take up fluid by macropinocytosis. The present study used fluorescent fluid-phase markers and GFP-labeled microtubules to visualize the uptake, dynamics, and fusion of early endosomes in Dictyostelium. Consecutive labeling with two fluorescent fluid-phase markers demonstrated that within the first few minutes after uptake, new macropinosomes underwent fusion with pre-existing endosomes. The fusing endosomes, which represent the mixing compartment, displayed extreme shape changes and rapid transport about the cell in association with microtubules. The great plasticity of endosomes at this stage of maturation was also evident by electron microscopy. The constant undulatory motion of microtubules was implemental in establishing contact with endosomes. Treatment of cells with agents that selectively disrupted either actin filaments or microtubules confirmed that endosome dynamics were microtubule based. Further maturation of endosomes led to loss of pleiomorphy in favor of a spherical shape, inability to fuse with new macropinosomes, and diminished motility.