title: LRRK2 autophosphorylation enhances its GTPase activity.
abstract: The leucine-rich repeat kinase (LRRK)-2 protein contains nonoverlapping GTPase and kinase domains, and mutation in either domain can cause Parkinson disease. GTPase proteins are critical upstream modulators of many effector protein kinases. In LRRK2, this paradigm may be reversed, as the kinase domain phosphorylates its own GTPase domain. In this study, we found that the ameba LRRK2 ortholog ROCO4 phosphorylates the GTPase domain [termed Ras-of-complex (ROC) domain in this family] of human LRRK2 on the same residues as the human LRRK2 kinase. Phosphorylation of ROC enhances its rate of GTP hydrolysis [from kcat (catalytic constant) 0.007 to 0.016 min(-1)], without affecting GTP or GDP dissociation kinetics [koff = 0.093 and 0.148 min(-1) for GTP and GDP, respectively). Phosphorylation also promotes the formation of ROC dimers, although GTPase activity appears to be equivalent between purified dimers and monomers. Modeling experiments show that phosphorylation induces conformational changes at the critical p-loop structure. Finally, ROC appears to be one of many GTPases phosphorylated in p-loop residues, as revealed by alignment of LRRK2 autophosphorylation sites with GTPases annotated in the phosphoproteome database. These results provide an example of a novel mechanism for kinase-mediated control of GTPase activity.
authors.affiliation: *Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, Center for Structural Biology, Department of Optometry, and Department of Surgery, The University of Alabama at Birmingham, Birmingham, Alabama, USA; and Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Liu
authors.affiliation: *Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, Center for Structural Biology, Department of Optometry, and Department of Surgery, The University of Alabama at Birmingham, Birmingham, Alabama, USA; and Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Mobley
authors.affiliation: *Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, Center for Structural Biology, Department of Optometry, and Department of Surgery, The University of Alabama at Birmingham, Birmingham, Alabama, USA; and Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: DeLucas
authors.affiliation: *Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, Center for Structural Biology, Department of Optometry, and Department of Surgery, The University of Alabama at Birmingham, Birmingham, Alabama, USA; and Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Kahn
authors.affiliation: *Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, Center for Structural Biology, Department of Optometry, and Department of Surgery, The University of Alabama at Birmingham, Birmingham, Alabama, USA; and Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA abwest@uab.edu.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: West
mesh_terms: D000595:Amino Acid Sequence; D000656:Amoeba / Q000201:enzymology; D020558:GTP Phosphohydrolases / Q000737:chemistry* / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D000071158:Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; D008969:Molecular Sequence Data; D010766:Phosphorylation; D055503:Protein Multimerization; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: D015800:Protozoan Proteins; D006160:Guanosine Triphosphate; C495280:LRRK2 protein, human; D000071158:Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; D017346:Protein Serine-Threonine Kinases; D020558:GTP Phosphohydrolases
keywords: G-protein; GTP-hydrolysis; Parkinson disease; ROC; phosphorylation