The Niemann-Pick C1 Protein Resides in a Vesicular Compartment Linked to Retrograde Transport of Multiple Lysosomal Cargo

Neufeld, Edward B.; Wastney, Meryl E.; Patel, Seema; Suresh, Sundar; Cooney, Adele; Dwyer, Nancy K.; Roff, Calvin F.; Ohno, Kousaku; Morris, Jill A.; Carstea, Eugene D.; Incardona, John P.; Strauss, Jerome F.; Vanier, Marie T.; Patterson, Marc C.; Brady, Roscoe O.; Pentchev, Peter G.; Blanchette‐Mackie, E. Joan

doi:10.1074/jbc.274.14.9627

Cited by 355 publications

(335 citation statements)

References 49 publications

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“…This sorting step can be impaired by administering either hydrophobic amines (Liscum and Faust, 1989) or antibodies to the endosome-specific lipid lysobisphosphatidic acid (Kobayashi et al, 1999) or by mutating the Niemann-Pick C disease (NPC1) gene (Neufeld et al, 1999). Importantly, many of the mutant GFP-hVPS4-induced vacuoles stained with the cholesterol-specific fluorescent marker filipin (Figure 8, A-H).…”

Section: Atpase-defective Mammalian Vps4 Binds Endosomal Compartmentsmentioning

confidence: 99%

ATPase-defective Mammalian VPS4 Localizes to Aberrant Endosomes and Impairs Cholesterol Trafficking

Bishop

Woodman

2000

MBoC

230

216

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The yeast vacuolar sorting protein Vps4p is an ATPase required for endosomal trafficking that couples membrane association to its ATPase cycle. To investigate the function of mammalian VPS4 in endosomal trafficking, we have transiently expressed wild-type or ATPase-defective human VPS4 (hVPS4) in cultured cells. Wild-type hVPS4 was cytosolic, whereas a substantial fraction of hVPS4 that was unable to either bind or hydrolyze ATP was localized to membranes, including those of specifically induced vacuoles. Vacuoles were exclusively endocytic in origin, and subsets of enlarged vacuoles stained with markers for each stage of the endocytic pathway. Sorting of receptors from the early endosome to the recycling compartment or to the trans-Golgi network was not significantly affected, and no mutant hVPS4 associated with these compartments. However, many hVPS4-induced vacuoles were substantially enriched in cholesterol relative to the endosomal compartments of untransfected cells, indicating that expression of mutant hVPS4 gives rise to a kinetic block in postendosomal cholesterol sorting. The phenotype described here is largely consistent with the defects in vacuolar sorting associated with class E vps mutants in yeast, and a role for mammalian VPS4 is discussed in this context.

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Section: Atpase-defective Mammalian Vps4 Binds Endosomal Compartmentsmentioning

confidence: 99%

ATPase-defective Mammalian VPS4 Localizes to Aberrant Endosomes and Impairs Cholesterol Trafficking

Bishop

Woodman

2000

MBoC

230

216

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“…Based on observations summarized above, it was anticipated that disruption of the Mln64 START domain would result in a phenotype similar to that of spontaneous mutations in the Npc1 gene in mice, including a progressive neurodegenerative disorder (ataxia, progressive motor deficits, and later death) and, at a cellular level, accumulation of free cholesterol in lysosomes (26,27). Humans lacking functional NPC1 or NPC2 have a similar phenotype.…”

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confidence: 99%

Targeted Mutation of the MLN64 START Domain Causes Only Modest Alterations in Cellular Sterol Metabolism

Kishida

Kostetskii

Zhang

et al. 2004

Journal of Biological Chemistry

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The StAR-related lipid transfer (START) domain, first identified in the steroidogenic acute regulatory protein (StAR), is involved in the intracellular trafficking of lipids. Sixteen mammalian START domain-containing proteins have been identified to date. StAR, a protein targeted to mitochondria, stimulates the movement of cholesterol from the outer to the inner mitochondrial membranes, where it is metabolized into pregnenolone in steroidogenic cells. MLN64, the START domain protein most closely related to StAR, is localized to late endosomes along with other proteins involved in sterol trafficking, including NPC1 and NPC2, where it has been postulated to participate in sterol distribution to intracellular membranes. To investigate the role of MLN64 in sterol metabolism, we created mice with a targeted mutation in the Mln64 START domain, expecting to find a phenotype similar to that in humans and mice lacking NPC1 or NPC2 (progressive neurodegenerative symptoms, free cholesterol accumulation in lysosomes). Unexpectedly, mice homozygous for the Mln64 mutant allele were viable, neurologically intact, and fertile. No significant alterations in plasma lipid levels, liver lipid content and distribution, and expression of genes involved in sterol metabolism were observed, except for an increase in sterol ester storage in mutant mice fed a high fat diet. Embryonic fibroblast cells transfected with the cholesterol side-chain cleavage system and primary cultures of granulosa cells from Mln64 mutant mice showed defects in sterol trafficking as reflected in reduced conversion of endogenous cholesterol to steroid hormones. These observations suggest that the Mln64 START domain is largely dispensable for sterol metabolism in mice.

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“…Cellular cholesterol enrichment, through endocytic uptake of low-density lipoprotein (LDL), alters the intracellular distribution of NPC1 protein from a finely dispersed granular pattern to sequestration in prominent cytoplasmic vesicles (7,8). These NPC1-containing vesicles are positive for lysosomal-associated membrane protein 2 (LAMP2) (7,9), are not enriched in lysosomal hydrolases (7), and are positive for the late endosomal marker proteins Rab7 (7) and Rab 9 (10). NPC1-containing late endosomes are critical for the retroendocytic trafficking of multiple lysosomal cargo (4,9).…”

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confidence: 99%

“…These NPC1-containing vesicles are positive for lysosomal-associated membrane protein 2 (LAMP2) (7,9), are not enriched in lysosomal hydrolases (7), and are positive for the late endosomal marker proteins Rab7 (7) and Rab 9 (10). NPC1-containing late endosomes are critical for the retroendocytic trafficking of multiple lysosomal cargo (4,9). Retroendocytic clearance of fluid phase markers, such as sucrose, from late endosomes is retarded by LDL-derived cellular enrichment of cholesterol (9).…”

mentioning

confidence: 99%

“…NPC1-containing late endosomes are critical for the retroendocytic trafficking of multiple lysosomal cargo (4,9). Retroendocytic clearance of fluid phase markers, such as sucrose, from late endosomes is retarded by LDL-derived cellular enrichment of cholesterol (9). We have recently shown that cholesterol modulates glycolipid sorting from NPC1-containing late endosomes into lysosomes (7).…”

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confidence: 99%

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Cessation of rapid late endosomal tubulovesicular trafficking in Niemann–Pick type C1 disease

Zhang

Dwyer²,

Love³

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

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126

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Niemann-Pick type C1 (NPC1) disease results from a defect in the NPC1 protein and is characterized by a pathological accumulation of cholesterol and glycolipids in endocytic organelles. We followed the biosynthesis and trafficking of NPC1 with the use of a functional green fluorescent protein-fused NPC1. Newly synthesized NPC1 is exported from the endoplasmic reticulum and requires transit through the Golgi before it is targeted to late endosomes. NPC1-containing late endosomes then move by a dynamic process involving tubulation and fission, followed by rapid retrograde and anterograde migration along microtubules. Cell fusion studies with normal and mutant NPC1 cells show that exchange of contents between late endosomes and lysosomes depends upon ongoing tubulovesicular late endocytic trafficking. In turn, rapid endosomal tubular movement requires an intact NPC1 sterol-sensing domain and is retarded by an elevated endosomal cholesterol content. We conclude that the neuropathology and cellular lysosomal lipid accumulation in NPC1 disease results, at least in part, from striking defects in late endosomal tubulovesicular trafficking. D efects of the NPC1 gene cause a severe endocytic accumulation of cholesterol in a variety of cellular and animal models of Niemann-Pick C1 (NPC1) disease (1, 2). The fatal damage in NPC1 disease is neurodegeneration starting from early life. The product of the NPC1 gene (NPC1) is composed of 1,278 aa and is predicted to contain 13 transmembrane domains (2, 3). NPC1 possesses a sterol-sensing domain (SSD) that is also found in two other proteins critical to maintaining cellular cholesterol homeostasis, the sterol response elementbinding protein cleavage-activating protein and the enzyme 3-hydroxy-3-methylglutaryl-CoA reductase (2, 4). The cDNA encoding human NPC1 corrects the defect in NPC1 mutant cells and facilitates clearance of the extensive lysosomal pools of cholesterol (2, 5). After biosynthesis of NPC1 in the endoplasmic reticulum, the protein is processed further in the Golgi apparatus (6); at steady state, it is associated with late endosomes. Cellular cholesterol enrichment, through endocytic uptake of low-density lipoprotein (LDL), alters the intracellular distribution of NPC1 protein from a finely dispersed granular pattern to sequestration in prominent cytoplasmic vesicles (7,8). These NPC1-containing vesicles are positive for lysosomal-associated membrane protein 2 (LAMP2) (7, 9), are not enriched in lysosomal hydrolases (7), and are positive for the late endosomal marker proteins Rab7 (7) and Rab 9 (10). NPC1-containing late endosomes are critical for the retroendocytic trafficking of multiple lysosomal cargo (4, 9). Retroendocytic clearance of fluid phase markers, such as sucrose, from late endosomes is retarded by LDL-derived cellular enrichment of cholesterol (9). We have recently shown that cholesterol modulates glycolipid sorting from NPC1-containing late endosomes into lysosomes (7). In this report, we have visualized functional green fluorescent protein-labeled...

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The Niemann-Pick C1 Protein Resides in a Vesicular Compartment Linked to Retrograde Transport of Multiple Lysosomal Cargo

Abstract: Niemann-Pick C disease (NP-CWe conclude that a distinctive organelle containing NPC1 mediates retrograde lysosomal transport of endocytosed cargo that is not restricted to sterol.

Cited by 355 publications

References 49 publications

ATPase-defective Mammalian VPS4 Localizes to Aberrant Endosomes and Impairs Cholesterol Trafficking

ATPase-defective Mammalian VPS4 Localizes to Aberrant Endosomes and Impairs Cholesterol Trafficking

Targeted Mutation of the MLN64 START Domain Causes Only Modest Alterations in Cellular Sterol Metabolism

Cessation of rapid late endosomal tubulovesicular trafficking in Niemann–Pick type C1 disease

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