Parkin mediates the mitochondrial dysfunction through mRpL18.

Area of Science:

• Neuroscience
• Cell Biology
• Genetics

Background:

• Parkin loss-of-function is linked to Parkinson's disease and mitochondrial dysfunction.
• Existing models suggest mitophagy defects or Mfn accumulation explain Parkin's role, but in vivo mechanisms remain unclear.

Purpose of the Study:

• To elucidate the in vivo mechanism by which Parkin loss leads to mitochondrial dysfunction.
• To investigate the roles of Marf and mRpL18 in Parkin-mediated mitochondrial morphology regulation.

Main Methods:

• Utilized Drosophila models to study Parkin's function in muscle tissue.
• Conducted a genome-wide screen to identify genetic modifiers of parkin loss-of-function.
• Employed RNA interference (RNAi) to assess the impact of gene knockdown.
• Analyzed protein-protein interactions and subcellular localization.

Main Results:

• Parkin loss impairs mitochondrial fission by causing accumulation of mRpL18, which inhibits the Drp1/Fis1 interaction.
• Parkin loss also promotes mitochondrial fusion by impairing Pink1-Parkin-mediated Marf degradation.
• Knockdown of either marf or mRpL18 rescues parkin RNAi-induced mitochondrial hyperfusion and associated fly wing phenotypes.

Conclusions:

• Parkin regulates mitochondrial morphology through a dual mechanism involving both fusion and fission pathways.
• Parkin deficiency leads to mitochondrial hyperfusion via impaired Marf degradation and mRpL18 accumulation.
• Targeting Marf or mRpL18 presents a potential therapeutic strategy for Parkinson's disease.