The Parkinson disease-associated protein kinase LRRK2 exhibits MAPKKK activity and phosphorylates MKK3/6 and MKK4/7, in vitro |
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Authors: | Christian Johannes Gloeckner Annette Schumacher Karsten Boldt† Marius Ueffing† |
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Institution: | Helmholtz Zentrum München, German Research Center for Environmental Health, Department of Protein Science, Neuherberg, Germany; Institute of Human Genetics, Klinikum Rechts der Isar, Technical University Munich, Munich, Germany |
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Abstract: | Autosomal dominant mutations in the human Leucine-Rich Repeat Kinase 2 ( LRRK2 ) gene represent the most common monogenetic cause of Parkinson disease (PD) and increased kinase activity observed in pathogenic mutants of LRRK2 is most likely causative for PD-associated neurotoxicity. The sequence of the LRRK2 kinase domain shows similarity to MAP kinase kinase kinases. Furthermore, LRRK2 shares highest sequence homology with mixed linage kinases which act upstream of canonical MAPKK and are involved in cellular stress responses. Therefore, we addressed the question if LRRK2 exhibits MAPKKK activity by systematically testing MAPKKs as candidate substrates, in vitro . We demonstrate that LRRK2 variants phosphorylate mitogen-activated protein kinase kinases (MAPKK), including MKK3 -4, -6 and -7. MKKs act upstream of the MAPK p38 and JNK mediating oxidative cell stress, neurotoxicity and apoptosis. The disease-associated LRRK2 G2019S and I2020T mutations show an increased phosphotransferase activity towards MKKs correlating with the activity shown for its autophosphorylation. Our findings present evidence of a new class of molecular targets for mutant LRRK2 that link to neurotoxicity, cellular stress, cytoskeletal dynamics and vesicular transport. |
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Keywords: | LRRK2 MKK3 MKK4 MKK6 MKK7 Parkinson disease |
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