English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

NPC (Niemann-Pick type C) disease is a rare lipidosis characterized by the accumulation of LDL (low-density lipoprotein)-derived non-esterified cholesterol in the E/L (endosomal/lysosomal) system. The gene products that are responsible for the two NPC complementation groups are distinct and dissimilar, yet their cellular and disease phenotypes are virtually indistinguishable. To investigate the relationship between NPC1 and NPC2 and their potential role in NPC disease pathogenesis, we have developed a method for the rapid and efficient isolation of late endocytic vesicles from mouse liver by magnetic chromatography. Late endosomes from Wt (wild-type) and NPC1 mice were found to differ not only in their cholesterol and sphingomyelin content, as expected, but also in their non-esterified ('free') fatty acid content, with NPC1 vesicles showing an approx. 7-fold increase in non-esterified fatty acid levels compared with Wt vesicles. Furthermore, we show that the NPC2 protein is in an incompletely deglycosylated form in NPC1 late endosomes by a mechanism that is specific to the NPC2 protein and not a global aberration of protein glycosylation/deglycosylation or trafficking, since NPC2 secreted from NPC1 cells is indistinguishable from that secreted from Wt cells. Also, a greater proportion of the normally soluble cellular NPC2 protein partitions with detergent-insoluble late endosomal internal membrane domains in NPC1 vesicles. In addition, we show that, although a small amount of the NPC2 protein associates with these membranes in Wt vesicles, this localization becomes much more pronounced in NPC1 vesicles. These results suggest that the function of the NPC2 protein may be compromised as well in NPC1 endosomes, which might explain the paradoxical phenotypic similarities of the two NPC disease complementation groups.

NPC1 late endosomes contain elevated levels of non-esterified (‘free’) fatty acids and an abnormally glycosylated form of the NPC2 protein