Rab proteins mediate Golgi transport of caveola-internalized glycosphingolipids and correct lipid trafficking in Niemann-Pick C cells.
Rab proteins mediate Golgi transport of caveola-internalized glycosphingolipids and correct lipid trafficking in Niemann-Pick C cells.
复制标题
DOI：
10.1172/jci15420
复制
发表时间：
2002-06
期刊：
影响因子：
--
通讯作者：
A. Choudhury;M. Dominguez;V. Puri;D. Sharma;K. Narita;C. Wheatley;D. Marks;R. Pagano
中科院分区：
文献类型：
--
作者：
A. Choudhury;M. Dominguez;V. Puri;D. Sharma;K. Narita;C. Wheatley;D. Marks;R. Pagano
我们最近发现，人类皮肤成纤维细胞内化荧光类似物的鞘糖脂乳糖神经酰胺和globoside几乎完全由网格蛋白独立的机制，涉及小窝。相比之下，鞘磷脂类似物通过网格蛋白依赖性和小窝途径大致相等地内化。在这里，我们进一步的特点是鞘糖脂的小窝途径，显示高尔基体靶向鞘脂内化通过小窝需要微管和磷酸肌醇3-激酶，并在细胞中抑制显性负Rab 7和Rab 9结构表达。此外，在尼曼-匹克C型（NP-C）脂质沉积病成纤维细胞中过表达野生型Rab 7或Rab 9（但不表达Rab 11）导致脂质运输缺陷的纠正，包括荧光乳糖神经酰胺和内源性GM（1）神经节苷脂的高尔基体靶向恢复，以及细胞内胆固醇储存的显著减少。我们的研究结果表明Rab 7和Rab 9在高尔基体靶向鞘糖脂中的作用，并提出了一种新的治疗方法，用于恢复NP-C细胞中正常的脂质运输。
We recently showed that human skin fibroblasts internalize fluorescent analogues of the glycosphingolipids lactosylceramide and globoside almost exclusively by a clathrin-independent mechanism involving caveolae. In contrast, a sphingomyelin analogue is internalized approximately equally via clathrin-dependent and caveolar routes. Here, we further characterized the caveolar pathway for glycosphingolipids, showing that Golgi targeting of sphingolipids internalized via caveolae required microtubules and phosphoinositol 3-kinases and was inhibited in cells expressing dominant-negative Rab7 and Rab9 constructs. In addition, overexpression of wild-type Rab7 or Rab9 (but not Rab11) in Niemann-Pick type C (NP-C) lipid storage disease fibroblasts resulted in correction of lipid trafficking defects, including restoration of Golgi targeting of fluorescent lactosylceramide and endogenous GM(1) ganglioside, and a dramatic reduction in intracellular cholesterol stores. Our results demonstrate a role for Rab7 and Rab9 in the Golgi targeting of glycosphingolipids and suggest a new therapeutic approach for restoring normal lipid trafficking in NP-C cells.