Identification of novel ATP13A2 interactors and their role in α-synuclein misfolding and toxicity

Hum Mol Genet. 2012 Sep 1;21(17):3785-94. doi: 10.1093/hmg/dds206. Epub 2012 May 29.

Abstract

Lysosomes are responsible for degradation and recycling of bulky cell material, including accumulated misfolded proteins and dysfunctional organelles. Increasing evidence implicates lysosomal dysfunction in several neurodegenerative disorders, including Parkinson's disease and related synucleinopathies, which are characterized by the accumulation of α-synuclein (α-syn) in Lewy bodies. Studies of lysosomal proteins linked to neurodegenerative disorders present an opportunity to uncover specific molecular mechanisms and pathways that contribute to neurodegeneration. Loss-of-function mutations in a lysosomal protein, ATP13A2 (PARK9), cause Kufor-Rakeb syndrome that is characterized by early-onset parkinsonism, pyramidal degeneration and dementia. While loss of ATP13A2 function plays a role in α-syn misfolding and toxicity, the normal function of ATP13A2 in the brain remains largely unknown. Here, we performed a screen to identify ATP13A2 interacting partners, as a first step toward elucidating its function. Utilizing a split-ubiquitin membrane yeast two-hybrid system that was developed to identify interacting partners of full-length integral membrane proteins, we identified 43 novel interactors that primarily implicate ATP13A2 in cellular processes such as endoplasmic reticulum (ER) translocation, ER-to-Golgi trafficking and vesicular transport and fusion. We showed that a subset of these interactors modified α-syn aggregation and α-syn-mediated degeneration of dopaminergic neurons in Caenorhabditis elegans, further suggesting that ATP13A2 and α-syn are functionally linked in neurodegeneration. These results implicate ATP13A2 in vesicular trafficking and provide a platform for further studies of ATP13A2 in neurodegeneration.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis elegans / drug effects
  • Caenorhabditis elegans / metabolism
  • Dopaminergic Neurons / drug effects
  • Dopaminergic Neurons / metabolism
  • Dopaminergic Neurons / pathology
  • Gene Knockdown Techniques
  • HEK293 Cells
  • Humans
  • Nerve Degeneration / metabolism
  • Nerve Degeneration / pathology
  • Protein Binding / drug effects
  • Protein Folding / drug effects*
  • Proton-Translocating ATPases / metabolism*
  • Reproducibility of Results
  • Two-Hybrid System Techniques
  • alpha-Synuclein / chemistry
  • alpha-Synuclein / metabolism*
  • alpha-Synuclein / toxicity*

Substances

  • ATP13A2 protein, human
  • alpha-Synuclein
  • Proton-Translocating ATPases