A STING-CASM-GABARAP Pathway Activates LRRK2 at Lysosomes

Mutations that increase LRRK2 kinase activity have been linked to Parkinson’s disease and Crohn’s disease. LRRK2 is also activated by lysosome damage evoked by chemical and pathogenic stimuli. However, the endogenous cellular mechanisms that control LRRK2 kinase activity are not well understood. In this study, we identify signaling through Stimulator of Interferon Genes (STING) as an upstream activator of LRRK2. This LRRK2 activation occurs via the Conjugation of ATG8 to Single Membranes (CASM) pathway. We furthermore establish that multiple chemical stimuli that perturb lysosomal homeostasis also converge on CASM to activate LRRK2. Although CASM mediates the lipidation of multiple ATG8 protein family members, LRRK2 lysosome recruitment and kinase activation is highly dependent on an interaction with the GABARAP member of this family. Collectively these results define a pathway that integrates multiple stimuli at lysosomes to control the kinase activity of LRRK2. Aberrant activation this pathway may be of relevance in both Parkinson’s and Crohn’s diseases.