A motif within the armadillo repeat of Parkinson's-linked LRRK2 interacts with FADD to hijack the extrinsic death pathway

Sci Rep. 2018 Feb 22;8(1):3455. doi: 10.1038/s41598-018-21931-8.

Abstract

In experimental models, both in vivo and cellular, over-expression of Parkinson's linked mutant leucine-rich repeat kinase 2 (LRRK2) is sufficient to induce neuronal death. While several cell death associated proteins have been linked to LRRK2, either as protein interactors or as putative substrates, characterization of the neuronal death cascade remains elusive. In this study, we have mapped for the first time the domain within LRRK2 that mediates the interaction with FADD, thereby activating the molecular machinery of the extrinsic death pathway. Using homology modeling and molecular docking approaches, we have identified a critical motif within the N-terminal armadillo repeat region of LRRK2. Moreover, we show that co-expression of fragments of LRRK2 that contain the FADD binding motif, or deletion of this motif itself, blocks the interaction with FADD, and is neuroprotective. We further demonstrate that downstream of FADD, the mitochondrial proteins Bid and Bax are recruited to the death cascade and are necessary for neuronal death. Our work identifies multiple novel points within neuronal death signaling pathways that could potentially be targeted by candidate therapeutic strategies and highlight how the extrinsic pathway can be activated intracellularly in a pathogenic context.

MeSH terms

  • Animals
  • Armadillo Domain Proteins / genetics
  • Armadillo Domain Proteins / metabolism*
  • BH3 Interacting Domain Death Agonist Protein / metabolism
  • Cell Death
  • Fas-Associated Death Domain Protein / metabolism*
  • HEK293 Cells
  • Humans
  • Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 / genetics
  • Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 / metabolism*
  • Mice
  • Molecular Docking Simulation
  • Neurons / cytology
  • Neurons / metabolism*
  • Parkinson Disease / metabolism*
  • Primary Cell Culture
  • Protein Interaction Domains and Motifs / genetics
  • Protein Interaction Mapping
  • Rats
  • Repetitive Sequences, Amino Acid
  • Signal Transduction
  • bcl-2-Associated X Protein / metabolism

Substances

  • Armadillo Domain Proteins
  • BAX protein, human
  • BH3 Interacting Domain Death Agonist Protein
  • BID protein, human
  • FADD protein, human
  • Fas-Associated Death Domain Protein
  • bcl-2-Associated X Protein
  • LRRK2 protein, human
  • Leucine-Rich Repeat Serine-Threonine Protein Kinase-2