XK is a partner for VPS13A: a molecular link between Chorea-Acanthocytosis and McLeod Syndrome

Mol Biol Cell. 2020 Oct 15;31(22):2425-2436. doi: 10.1091/mbc.E19-08-0439-T. Epub 2020 Aug 26.

Abstract

Vps13 is a highly conserved lipid transfer protein found at multiple interorganelle membrane contact sites where it mediates distinct processes. In yeast, recruitment of Vps13 to different contact sites occurs via various partner proteins. In humans, four VPS13 family members, A-D, are associated with different diseases. In particular, vps13A mutants result in the neurodegenerative disorder Chorea-Acanthocytosis (ChAc). ChAc phenotypes resemble those of McLeod Syndrome, caused by mutations in the XK gene, suggesting that XK could be a partner protein for VPS13A. XK does, in fact, exhibit hallmarks of a VPS13A partner: it forms a complex with VPS13A in human cells and, when overexpressed, relocalizes VPS13A from lipid droplets to subdomains of the endoplasmic reticulum. Introduction of two different ChAc disease-linked missense mutations into VPS13A prevents this XK-induced relocalization. These results suggest that dysregulation of a VPS13A-XK complex is the common basis for ChAc and McLeod Syndrome.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Transport Systems, Neutral / genetics
  • Amino Acid Transport Systems, Neutral / metabolism*
  • Endoplasmic Reticulum / metabolism
  • Endosomes / metabolism
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Lipid Droplets / metabolism
  • Mitochondria / metabolism
  • Mitochondrial Membranes / metabolism
  • Neuroacanthocytosis / genetics
  • Neuroacanthocytosis / metabolism*
  • Vesicular Transport Proteins / genetics
  • Vesicular Transport Proteins / metabolism*

Substances

  • Amino Acid Transport Systems, Neutral
  • VPS13A protein, human
  • Vesicular Transport Proteins
  • XK protein, human

Supplementary concepts

  • Neuroacanthocytosis, Mcleod Type