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Biology subjects

Beilina, A.

Publications and source records attributed to Beilina, A..

2 recordsLinked to original sources

LRRK2 mediates tubulation and vesicle sorting from membrane damaged lysosomes

Mutations in the leucine rich repeat kinase 2 (LRRK2) gene are a cause of familial and sporadic Parkinsons disease (PD). Nonetheless, the biological functions of LRRK2 remain incompletely understood. Here, we observed that LRRK2 is recruited to lysosomes that have a ruptured membrane. Using unbiased proteomics, we observed that LRRK2 is able to recruit the motor adaptor protein JIP4 to permeabilized lysosomes in a kinase-dependent manner through the phosphorylation of RAB35 and RAB10. Super-resolution live cell imaging microscopy and FIB-SEM revealed that once at the lysosomal membrane, JIP4 promotes the formation of LAMP1-negative lysosomal tubules that release membranous content from ruptured lysosomes. Released vesicular structures are able to interact with other lysosomes. Thus, we described a new process that uses lysosomal tubulation to release vesicular structures from permeabilized lysosomes. LRRK2 orchestrates this process that we name LYTL (LYsosomal Tubulation/sorting driven by LRRK2) that, given the central role of the lysosome in PD, is likely to be disease relevant.

cell biology

Mutations in Auxilin cause parkinsonism via impaired clathrin-mediated trafficking at the Golgi apparatus and synapse

Parkinsons disease (PD) is a common neurodegenerative motor disorder characterized in part by neuropathological lesions in the nigrostriatal pathway. Loss of function mutations in Auxilin, the major neuronal clathrin uncoating protein, cause an aggressive form of juvenile onset PD. How mutations in Auxilin cause PD, is currently not understood. Here, we generated a novel mouse model carrying an endogenous pathogenic Auxilin mutation that phenocopies neurological features observed in patients, including motor impairments and seizures. Unbiased mapping of the Auxilin interactome identified synaptic and Golgi-resident clathrin adaptor proteins as novel interactors. Impaired clathrin-mediated trafficking in mutant Auxilin mice, both at the Golgi and the synapse, results in neuropathological lesions in the nigrostriatal pathway. Collectively, these results provide molecular mechanisms of PD pathogenesis in Auxilin mutation carriers, reinforcing a key role for clathrin-mediated trafficking in PD, and expand our understanding of the cellular function of Auxilin.

neuroscience