The E3 ligase TRIM1 ubiquitinates LRRK2 and controls its localization, degradation, and toxicity

Abstract

Missense mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common cause of familial Parkinson’s disease (PD); however, pathways regulating LRRK2 subcellular localization, function, and turnover are not fully defined. We performed quantitative mass spectrometry–based interactome studies to identify 48 novel LRRK2 interactors, including the microtubule-associated E3 ubiquitin ligase TRIM1 (tripartite motif family 1). TRIM1 recruits LRRK2 to the microtubule cytoskeleton for ubiquitination and proteasomal degradation by binding LRRK2911–919, a nine amino acid segment within a flexible interdomain region (LRRK2853–981), which we designate the “regulatory loop” (RL). Phosphorylation of LRRK2 Ser910/Ser935 within LRRK2 RL influences LRRK2’s association with cytoplasmic 14-3-3 versus microtubule-bound TRIM1. Association with TRIM1 modulates LRRK2’s interaction with Rab29 and prevents upregulation of LRRK2 kinase activity by Rab29 in an E3-ligase–dependent manner. Finally, TRIM1 rescues neurite outgrowth deficits caused by PD-driving mutant LRRK2 G2019S. Our data suggest that TRIM1 is a critical regulator of LRRK2, controlling its degradation, localization, binding partners, kinase activity, and cytotoxicity.

Endogenous Rab38 regulates LRRK2’s membrane recruitment and substrate Rab phosphorylation in melanocytes

“…Thus far, endogenous LRRK2 has been conclusively visualized by IF only in macrophages stimulated to induce LRRK2 expression ( i.e. treated with interferon-γ or LPS) and/or treated with lysosomotropic agents to sequester LRRK2 to enlarged lysosomes ( 3 , 37 , 38 ). For our studies in melanocytes, we therefore expressed exogenous tagged LRRK2.…”

“…LRRK2 encodes a 286 kDa protein with two catalytic domains: a Ras of complex GTPase domain linked by a C terminus of Roc domain to a serine-threonine kinase ( 2 ). The remainder of the LRRK2 protein consists of protein-protein interaction domains (armadillo [ARM], ankyrin [ANK], leucine-rich repeat [LRR], and WD40 repeats) as well as a regulatory loop region between the ANK and LRR domains that can dictate LRRK2-binding partners and subcellular localization ( 3 ). How LRRK2 drives PD is not known.…”

“…Second, Rab32 and Rab38 have restricted cell and tissue expression and are highly expressed in cells that produce lysosome-related organelles (LROs), such as melanocytes (producing melanosomes), alveolar type II pneumocytes (producing lamellar bodies), and numerous inflammatory cells including macrophages and neutrophils ( 23 , 24 ). All of these cell types additionally express high levels of LRRK2, potentially suggesting a functional interaction ( 3 , 25 , 26 , 27 ). Most importantly, LRRK2 knockout or LRRK2 kinase inhibition causes striking buildup of enlarged lamellar bodies in alveolar type II pneumocytes in animal models, including nonhuman primates ( 28 , 29 ).…”

Regulation of LRRK2 mRNA stability by ATIC and its substrate AICAR through ARE‐mediated mRNA decay in Parkinson's disease

“…How LRRK2 expression levels are regulated is currently an important yet understudied area in PD pathogenesis. Several studies have focused on the regulation of LRRK2 protein stability (Ding & Goldberg, 2009; Ko et al , 2009; Nucifora Jr. et al , 2016; Stormo et al , 2022). However, the regulation of LRRK2 mRNA decay has not been reported.…”

It’s a TRIM-endous view from the top: the varied roles of TRIpartite Motif proteins in brain development and disease

“…LRRK2 is a cytoskeleton remodelling protein that is crucial in normal neuronal morphogenesis and is one of the most frequently mutated proteins in familial PD, where it both promotes neurotoxic protein aggregation and prevents the clearance of aggregates by autophagy ( Jaleel et al, 2007 ; Parisiadou et al, 2009 ). TRIM1 is therefore implicated in both neurodevelopment and PD because it can drive the ubiquitin-mediated degradation of wild-type or mutant LRRK2 ( Stormo et al, 2022 ). Given that TRIM1 and TRIM18 are both expressed in the brain and have been shown to interact, it would be interesting to investigate whether their interplay impacts their regulation of tau and LRKK2, respectively.…”