Functional interaction of Parkinson's disease-associated LRRK2 with members of the dynamin GTPase superfamily

Abstract

Mutations in LRRK2 cause autosomal dominant Parkinson's disease (PD). LRRK2 encodes a multi-domain protein containing GTPase and kinase domains, and putative protein–protein interaction domains. Familial PD mutations alter the GTPase and kinase activity of LRRK2 in vitro. LRRK2 is suggested to regulate a number of cellular pathways although the underlying mechanisms are poorly understood. To explore such mechanisms, it has proved informative to identify LRRK2-interacting proteins, some of which serve as LRRK2 kinase substrates. Here, we identify common interactions of LRRK2 with members of the dynamin GTPase superfamily. LRRK2 interacts with dynamin 1–3 that mediate membrane scission in clathrin-mediated endocytosis and with dynamin-related proteins that mediate mitochondrial fission (Drp1) and fusion (mitofusins and OPA1). LRRK2 partially co-localizes with endosomal dynamin-1 or with mitofusins and OPA1 at mitochondrial membranes. The subcellular distribution and oligomeric complexes of dynamin GTPases are not altered by modulating LRRK2 in mouse brain, whereas mature OPA1 levels are reduced in G2019S PD brains. LRRK2 enhances mitofusin-1 GTP binding, whereas dynamin-1 and OPA1 serve as modest substrates of LRRK2-mediated phosphorylation in vitro. While dynamin GTPase orthologs are not required for LRRK2-induced toxicity in yeast, LRRK2 functionally interacts with dynamin-1 and mitofusin-1 in cultured neurons. LRRK2 attenuates neurite shortening induced by dynamin-1 by reducing its levels, whereas LRRK2 rescues impaired neurite outgrowth induced by mitofusin-1 potentially by reversing excessive mitochondrial fusion. Our study elucidates novel functional interactions of LRRK2 with dynamin-superfamily GTPases that implicate LRRK2 in the regulation of membrane dynamics important for endocytosis and mitochondrial morphology.

Cellular processes associated with LRRK2 function and dysfunction

“…In mammalian cells, interaction was seen between LRRK2 and the dynamin GTPase superfamily 123 involved in membrane scission during clathrin‐associated endocytosis. In Drosophila , LRRK2 was shown to phosphorylate EndoA, decreasing EndoA affinity for membranes and affecting EndoA‐dependent membrane tubulation.…”

Unique Functional and Structural Properties of the LRRK2 Protein ATP-binding Pocket

“…LRRK2 possesses significant intrinsic cis-autophosphorylation (and not trans-autophosphorylation) (26) activities and only weakly phosphorylates other substrate proteins in vitro, such as generic substrates and interacting proteins (3,27). In designing LRRK2 small molecule kinase inhibitors, it may be desirable to preferentially target trans over cis LRRK2 kinase activities for therapeutic effects.…”

Dynamin Functions and Ligands: Classical Mechanisms Behind

“…Mutations of Parkin, an E3 ubiquitin protein ligase, lead to autosomal juvenile-onset of PD. Endophilin binds to the Ubi domain of Parkin via the SH3D and is said to become ubiquitinated (Wang et al, 2011;Stafa et al, 2014). Parkin levels significantly increase in the brain and fibroblasts of endophilin mutant mice (Cao et al, 2014).…”