guanosine-diphosphate and Parkinson-Disease

Mutations in the human leucine-rich repeat kinase 2 (LRRK2) are the most frequent cause of hereditary Parkinson's disease (PD). LRRK2 belongs to the Roco family of proteins, which are characterized by the presence of a Ras of complex proteins domain (Roc), a C-terminal of Roc domain (COR) and a kinase domain. Despite intensive research, much remains unknown about activity and the effect of PD-associated mutations. Recent biochemical and structural studies suggest that LRRK2 and Roco proteins are noncanonical G-proteins that do not depend on guanine nucleotide exchange factors or GTPase-activating proteins for activation. In this review, we will discuss the unusual G-protein cycle of LRRK2 in the context of the complex intramolecular LRRK2 activation mechanism.

Topics: GTP-Binding Proteins; Guanine Nucleotide Exchange Factors; Guanosine Diphosphate; Guanosine Triphosphate; Humans; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; Models, Biological; Mutation; Parkinson Disease; Phosphorylation

Mutation in leucine-rich repeat kinase 2 (LRRK2) is a common cause of familial Parkinson's disease (PD). Recently, we showed that a disease-associated mutation R1441H rendered the GTPase domain of LRRK2 catalytically less active and thereby trapping it in a more persistently "on" conformation. However, the mechanism involved and characteristics of this on conformation remained unknown. Here, we report that the Ras of complex protein (ROC) domain of LRRK2 exists in a dynamic dimer-monomer equilibrium that is oppositely driven by GDP and GTP binding. We also observed that the PD-associated mutations at residue 1441 impair this dynamic and shift the conformation of ROC to a GTP-bound-like monomeric conformation. Moreover, we show that residue Arg-1441 is critical for regulating the conformational dynamics of ROC. In summary, our results reveal that the PD-associated substitutions at Arg-1441 of LRRK2 alter monomer-dimer dynamics and thereby trap its GTPase domain in an activated state.

Topics: Amino Acid Substitution; Guanosine Diphosphate; Guanosine Triphosphate; HEK293 Cells; Humans; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; Mutation, Missense; Parkinson Disease; Protein Domains; Protein Multimerization

Mutations in Leucine Rich Repeat Kinase 2 (LRRK2) are the leading genetic cause of Parkinson's disease (PD). LRRK2 is predicted to contain kinase and GTPase enzymatic domains, with recent evidence suggesting that the kinase activity of LRRK2 is central to the pathogenic process associated with this protein. The GTPase domain of LRRK2 plays an important role in the regulation of kinase activity. To investigate how the GTPase domain might be related to disease, we examined the GTP binding and hydrolysis properties of wild type and a mutant form of LRRK2. We show that LRRK2 immunoprecipitated from cells has a detectable GTPase activity that is disrupted by a familial mutation associated with PD located within the GTPase domain, R1441C.

Topics: Amino Acid Substitution; Animals; Chlorocebus aethiops; COS Cells; GTP Phosphohydrolases; Guanosine Diphosphate; Guanosine Triphosphate; Humans; Hydrolysis; Immunoblotting; Immunoprecipitation; Kinetics; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; Mutation; Parkinson Disease; Protein Binding; Protein Serine-Threonine Kinases