LRRK2 interacts with the vacuolar-type H+-ATPase pump a1 subunit to regulate lysosomal function.

Area of Science:

• Neuroscience
• Cell Biology
• Genetics

Background:

• Lysosomal dysfunction is central to Parkinson's disease (PD) pathogenesis.
• The precise molecular mechanisms linking leucine-rich repeat kinase 2 (LRRK2) to lysosomal defects remain unclear.

Purpose of the Study:

• To investigate the role of LRRK2, including common PD-associated mutations (G2019S, R1441C), in regulating lysosome biology and autophagy.
• To identify novel molecular interactions and therapeutic targets for LRRK2-mediated lysosomal dysfunction in PD.

Main Methods:

• Primary neuron cultures expressing wild-type (hWT) or mutant LRRK2 (G2019S, R1441C).
• In vivo studies using aged LRRK2 transgenic animal models.
• Pharmacological inhibition of LRRK2 kinase activity using MLi-2 and PF-06447475.
• Analysis of autophagosome production, lysosome fusion, lysosomal pH, and vATPase a1 subunit interactions.

Main Results:

• LRRK2-G2019S and hWT-LRRK2 inhibited autophagosome production.
• LRRK2-R1441C impaired autophagosome-lysosome fusion and increased lysosomal pH.
• LRRK2-R1441C mutation disrupted binding to the vATPase a1 subunit, reducing its levels and causing mislocalization.
• LRRK2 kinase activity was not essential for the R1441C-mediated autolysosome maturation defect.
• Modulating lysosomal zinc rescued vATPase a1 levels and cellular phenotypes in R1441C models.

Conclusions:

• LRRK2 plays a significant role in maintaining lysosomal function and autophagy.
• A novel interaction between LRRK2 and the vATPase a1 subunit is identified, crucial for lysosomal homeostasis.
• Targeting the LRRK2-vATPase a1 interaction or modulating lysosomal zinc presents potential therapeutic avenues for PD.