Dynamin self-assembles into rings suggesting a mechanism for coated vesicle budding

来自 EBSCO

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摘要：

DYNAMIN, a 100K member of the GTPase superfamily 1 , is the mammalian homologue of the Drosophila shibire gene product 2,3 . Mutations in shibire cause a defect in endocytosis leading to accumulation of coated pits and deep imaginations at the plasma membrane of all tissues examined 4,5 . Similarly, invaginated coated pits accumulate in mammalian cells overexpressing dominant-negative mutants of dynamin, establishing that dynamin is required for the formation of 'constricted' coated pits and for coated vesicle budding 6 . Whether dynamin functions in the classic GTPase mode as a molecular switch to regulate events leading to coated vesicle budding or instead actively participates as a mechanochemical enzyme driving coated vesicle formation is unclear 7 . Here we show that dynamin spontaneously self-assembles into rings and stacks of interconnected rings, comparable in dimension to the 'collars' observed at the necks of invaginated coated pits that accumulate at synaptic terminals in shibire flies 4 . We propose that invaginated coated pits become constricted by the assembly of dynamin into rings around their necks. A concerted conformational change would then close the rings and pinch off the budding coated vesicles.

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关键词：

Coated Vesicles GTP Phosphohydrolases physiology Clathrin Recombinant Proteins 有膜囊泡

DOI：

10.1038/374190a0

被引量：

1732

年份：

1995