Effects of mutant rat dynamin on endocytosis.
Effects of mutant rat dynamin on endocytosis.
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DOI：
10.1083/jcb.122.3.565
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发表时间：
1993-08
期刊：
影响因子：
--
通讯作者：
Vallee RB
中科院分区：
文献类型：
--
作者：
Herskovits JS;Burgess CC;Obar RA;Vallee RB
Dynamin是一种100kD的微管激活的GTP酶。最近的证据表明，与果蝇基因shibire的产物具有高度的序列同源性，这种突变阻止了突触小泡的循环，更广泛地说，阻止了质膜上有涂层和无涂层的小泡的形成。我们现在已经用野生型和突变型Dynamin cDNA转染了培养的哺乳动物COS-7细胞。Dynamin与GTP结合的共同序列元件中的点突变相当于ras中的显性负突变，以及Dynamin整个GTP结合域的NH2末端缺失，阻止转铁蛋白的摄取，并改变网状蛋白重链和α-而不是伽马-适配素的分布。COOH末端的缺失逆转了这些效应，将这部分动力素确定为与内吞途径的其他成分相互作用的部位。野生型和突变型动力素的过度表达都不会影响微管的分布。这些结果证明了Dynamin和GTP在受体介导的内吞作用的初始阶段具有特定的作用。
Dynamin is a 100-kD microtubule-activated GTPase. Recent evidence has revealed a high degree of sequence homology with the product of the Drosophila gene shibire, mutations in which block the recycling of synaptic vesicles and, more generally, the formation of coated and non- coated vesicles at the plasma membrane. We have now transfected cultured mammalian COS-7 cells with both wild-type and mutant dynamin cDNAs. Point mutations in the GTP-binding consensus sequence elements of dynamin equivalent to dominant negative mutations in ras, and an NH2- terminal deletion of the entire GTP-binding domain of dynamin, block transferrin uptake and alter the distribution of clathrin heavy chain and alpha-, but not gamma-, adaptin. COOH-terminal deletions reverse these effects, identifying this portion of dynamin as a site of interaction with other components of the endocytic pathway. Over- expression of neither wild-type nor mutant forms of dynamin affected the distribution of microtubules. These results demonstrate a specific role for dynamin and for GTP in the initial stages of receptor-mediated endocytosis.