A STING-CASM-GABARAP Pathway Activates LRRK2 at Lysosomes

Abstract

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.

Lysosome damage triggers acute formation of ER to lysosomes membrane tethers mediated by the bridge-like lipid transport protein VPS13C

“…To validate with a biochemical approach the recruitment of VPS13C to lysosomes in response to LLOMe and to determine whether such recruitment is also observed for endogenous untagged VPS13C, we used a previously described technique for the purification of lysosomes. The method is based on a pulse incubation of live cells with dextran-conjugated superparamagnetic iron oxide nanoparticles (SPIONs) followed by a chase to allow traffic of the particles to lysosomes, and subsequent cell lysis and recovery of lysosomes on a magnetic column (15,33,34). Western blot analysis of the magnetically isolated material revealed abundant presence of Lamp1, but not of GM130 (Golgi marker) and PDI (a luminal ER marker), confirming the successful and specific isolation of lysosomes (Fig.…”

“…In view of the link of both LRRK2 and VPS13C to PD, we investigated potential temporal relationships between VPS13C and LRRK2 recruitment. As various perturbations that induce LRRK2 recruitment and activation do so by triggering the conjugation of ATG8 to single membranes (CASM) process (34,55), we focused on agents that regulate this pathway (Fig. 5A).…”

“…A recruitment of VPS13C to lysosomes in response to nigericin was also recently reported by a mass spectrometry analysis of purified lysosomes (56). However, saliphenylhalamide (SaliP), another agent that increases lysosomal PH and is a well-characterized CASM and LRRK2 activator (34,57), failed to recruit VPS13C (Fig. 5C top) although it induced a loss of LysoView TM 633 (a pH indicator) fluorescence proving its effectiveness in elevating lysosomal pH (Fig.…”

Opposing actions of JIP4 and RILPL1 provide antagonistic motor force to dynamically regulate membrane reformation during lysosomal tubulation/sorting driven by LRRK2

“…LYTL is orchestrated by Leucine-rich repeat kinase 2 (LRRK2), a large kinase basally located in the cytosol that is activated at membranes ( Bonet-Ponce and Cookson, 2022a ) where it phosphorylates a subset of RAB GTPases ( Steger et al, 2016 ; Kluss et al, 2022b ). Recent evidence indicates that LRRK2 is recruited to ruptured lysosomes via RAB12 ( Wang et al, 2023 ; Dhekne et al, 2023 ) and the CASM machinery ( Bentley-DeSousa and Ferguson, 2023 ; Eguchi et al, 2024 ), where it phosphorylates and brings pRAB proteins to the lysosomal membrane ( Eguchi et al, 2018 ; Herbst et al, 2020 ; Bonet-Ponce et al, 2020 ). Subsequently, pRAB10 recruits its effector JIP4 (C-jun-amino-terminal kinase-interacting protein 4, a motor adaptor protein) that promotes the formation of a lysosomal tubule negative for lysosomal membrane markers ( Bonet-Ponce et al, 2020 ; Bonet-Ponce and Cookson, 2022b ; Kluss et al, 2022a ).…”