The deposit of polyubiquitinated aggregates continues to be implicated in the pathophysiology of Parkinson’s disease (PD) and growing evidence indicates that selective autophagy plays a critical role in the clearance of ubiquitin-positive protein aggregates by autophagosomes. LRRK2 via selective autophagy. In the present study we found that p62/SQSTM-1 physically interacts with LRRK2 as a selective autophagic receptor. The overexpression of p62 leads to the robust degradation of LRRK2 through the autophagy-lysosome pathway. In addition LRRK2 indirectly regulates Ser351 and Ser403 phosphorylation of p62. Of particular interest the interaction between phosphorylated p62 and Keap1 is reduced by LRRK2 overexpression. Disodium (R)-2-Hydroxyglutarate Therefore we propose that the interplay between LRRK2 and p62 may contribute to the pathophysiological function and homeostasis of LRRK2 protein. Introduction The ubiquitin-proteasome system (UPS) and autophagy-lysosome pathway (ALP) are the major intracellular protein degradation pathways in eukaryotic cells. They were originally thought to function independently however accumulating evidence suggests that there is a crosstalk between these pathways with shared components [1-5]. Recent studies have indicated that several adaptor proteins such as p62/sequestosome-1 (p62/SQSTM-1 hereafter referred to as p62) neighbor of BRCA1 gene 1 (NBR1) nuclear dot protein 52 (NDP52) and optineurin (OPTN) serve as selective autophagy receptors that link polyubiquitinated cargoes to the autophagic machinery [6-12]. These receptors contain a microtubule-associated protein 1A/1B-light chain 3 (LC3)-interaction region (LIR) and a ubiquitin-associated (UBA) domain which binds to ubiquitin and Disodium (R)-2-Hydroxyglutarate to the mammalian Atg8 homologue LC3/GABARAP/Gate16 family respectively [13 14 Among those receptors p62 is the first selective autophagy receptor known to be responsible for the autophagic clearance of ubiquitin aggregates [13 15 The p62 protein is a multi-functional autophagy adaptor that was initially identified as a ligand of the Src homology 2 (SH2) domain of p56lck [16]. p62 is a receptor for ubiquitinated substrates that are sequestered into autophagosomes and it regulates protein aggregate formation [1 2 17 Indeed p62 is the major component of the ubiquitin-containing inclusions in various neurodegenerative diseases such as Parkinson’s disease (PD) [18 19 Moreover loss of p62 suppresses the appearance of polyubiquitinated aggregates in autophagy-deficient mice [20]. However the exact molecular mechanisms and pathophysiological functions of p62 in PD remain unknown. Leucine-rich repeat kinase 2 (LRRK2) is definitely a large multi-domain protein with both GTPase and kinase activity [21-23]. Several mutations in LRRK2 have been identified as the most common genetic causes of PD. G2019S probably the most common mutation enhances LRRK2 kinase activity which is definitely associated with neuronal toxicity and neurodegeneration. LRRK2 is definitely degraded via the UPS by interacting with the carboxyl terminus of Disodium (R)-2-Hydroxyglutarate HSP70-interacting protein (CHIP) which as a result protects against cytotoxicity induced by LRRK2 [24 25 In addition alterations in autophagy are consistently observed in the overexpression as well as the knockdown of LRRK2 [18 24 Recently LRRK2 was found to be degraded in lysosomes through chaperone-mediated autophagy (CMA) whereas the G2019S LRRK2 mutant is definitely more likely eliminated from the UPS and macroautophagy [26]. Nevertheless the mechanism of LRRK2 stability rules by selective autophagic receptors remains to be elucidated. In the present study we examined the functional part of p62 a representative selective autophagic receptor in regulating the stability of LRRK2. We in the beginning recognized that p62 regulates LRRK2 turnover via autophagy-lysosomal degradation in heterologous cells and neurons. Then we shown that LRRK2 indirectly regulates the phosphorylation state and Keap1 binding of p62. Taken collectively our Disodium (R)-2-Hydroxyglutarate data display that p62-mediated selective autophagy is necessary for LRRK2 degradation which may underlie the pathogenesis of PD. Materials and Methods Ethics statement The use and care Rabbit Polyclonal to ABHD12. of animals used in this study followed the guidelines of the Seoul National University Institutional Animal Care and Use Committee. Timed-pregnant Sprague-Dawley rats were from the Orient Bio (Seongnam Korea) and separately housed in standard cages during a period of acclimation with free access to food and water. Rats were kept inside a controlled room at a constant heat (22 ± 2°C) and humidity (50 ± 10%) on a 12 h light/dark cycle before.