Clathrin-independent pinocytosis is induced in cells overexpressing a temperature-sensitive mutant of dynamin.
Clathrin-independent pinocytosis is induced in cells overexpressing a temperature-sensitive mutant of dynamin.
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DOI：
10.1083/jcb.131.1.69
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发表时间：
1995-10
期刊：
影响因子：
--
通讯作者：
Schmid SL
中科院分区：
文献类型：
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作者：
Damke H;Baba T;van der Bliek AM;Schmid SL
一个稳定的HeLa细胞系表达的发动蛋白突变体，dynts，表现出内吞网格蛋白包被囊泡形成的温度敏感性缺陷。Dynts携带点突变G273D，对应于果蝇shibirets1等位基因。受体介导的内吞作用中的ts缺陷显示出快速发作（<5分钟）并且容易可逆。在非允许温度（38 ℃）下，HRP摄取仅部分受到抑制。此外，当细胞保持在非允许的温度下时，流体相摄取在30分钟内完全恢复到野生型水平，而受体介导的内吞作用仍然受到抑制。残留的HRP摄取后早期转移到非允许的温度和诱导的HRP摄取后发生的恢复是不敏感的胞质酸化的条件下，有效地抑制受体介导的内吞Tfn。总之，这些结果表明，发动蛋白和网格蛋白的非依赖性机制有助于HeLa细胞中的总组成性胞饮，并且dynts细胞通过诱导替代的内吞途径快速且完全地补偿网格蛋白依赖性内吞作用的损失。
A stable HeLa cell line expressing a dynamin mutant, dynts, exhibits a temperature-sensitive defect in endocytic clathrin-coated vesicle formation. Dynts carries a point mutation, G273D, corresponding to the Drosophila shibirets1 allele. The ts-defect in receptor-mediated endocytosis shows a rapid onset (< 5 min) and is readily reversible. At the nonpermissive temperature (38 degrees C) HRP uptake is only partially inhibited. Moreover, when cells are held at the nonpermissive temperature, fluid phase uptake fully recovers to wild-type levels within 30 min, while receptor-mediated endocytosis remains inhibited. The residual HRP uptake early after shift to the nonpermissive temperature and the induced HRP uptake that occurs after recovery are insensitive to cytosol acidification under conditions that potently inhibit receptor-mediated endocytosis of Tfn. Together, these results suggest that a dynamin- and clathrin-independent mechanism contributes to the total constitutive pinocytosis in HeLa cells and that dynts cells rapidly and completely compensate for the loss of clathrin- dependent endocytosis by inducing an alternate endocytic pathway.