Browsing by Subject "LRRK2"
Now showing 1 - 6 of 6
Results Per Page
Sort Options
Item High Throughput Screening for Modulators of LRRK2 GTPase Activity(2021-06) Gray, Derrick Allen; Hoang, Quyen Q.; Aoki, Scott; Vilseck, Jonah Z.Parkinson's disease (PD) is a progressive neurodegenerative disorder that affects over 10 million people. Treatments for PD are limited to symptom mitigation with no means of stopping or slowing disease progression. Mutations within the protein leucine- rich repeat kinase 2 (LRRK2) are the most common cause of familial PD and are indistinguishable from the more common sporadic cases. Identifying molecules capable of modulating LRRK2 GTPase activity may serve as the foundation for future development of novel PD therapeutics. We recently discovered that the G-domain (ROC) of LRRK2 is capable of transitioning between monomer and dimer form in solution upon GTP/GDP binding. R1441C/G/H pathogenic mutations were demonstrated to alter this dynamic shifting toward a monomeric ROC conformation while decreasing GTPase activity. Using our ROC dimeric crystal structure, we strategically introduced disulfide bonds to generate locked monomer and locked dimer states. Monomeric ROC was shown to increase GTPase activity while the dimeric form decreased activity. Solvent mapping performed using the dimeric ROC crystal structure and a homology model of the ROC monomer revealed a binding hotspot at the ROC dimeric interface and adjacent to the R1441 residue in the monomeric model. In this study our goal was to identify more compounds capable of influencing GTPase activity. We performed high throughput screening of ROC against two compound libraries (LOPAC1280 and ChemBridge 50K) in a GTP binding assay. Twenty-three hits were identified and four compounds were further investigated in dose-response experiments. 3,4-Methylenedioxy-beta nitrostyrene (MNS) was demonstrated to decrease GTP binding and inhibit GTPase activity (IC50=23.92μM) while the compound N-phenylanthranilic acid increased GTP binding (EC50=4.969μM) and decreased GTPase activity. Identification of these compounds is the first step in the development of a novel PD therapeutic targeting the G-domain of LRRK2.Item Novel recruitment strategy to enrich for LRRK2 mutation carriers(Wiley, 2015-09) Foroud, Tatiana; Smith, Danielle; Jackson, Jacqueline; Verbrugge, Jennifer; Halter, Cheryl; Wetherill, Leah; Sims, Katherine; Xin, Winnie; Arnedo, Vanessa; Lasch, Shirley; Marek, Kenneth; Department of Medical and Molecular Genetics, IU School of MedicineThe LRRK2 G2019S mutation is found at higher frequency among Parkinson disease (PD) patients of Ashkenazi Jewish (AJ) ancestry. This study was designed to test whether an internet-based approach could be an effective approach to screen and identify mutation carriers. Individuals with and without PD of AJ ancestry were recruited and consented through an internet-based study website. An algorithm was applied to a series of screening questions to identify individuals at increased risk to carry the LRRK2 G2019S mutation. About 1000 individuals completed the initial screening. Around 741 qualified for mutation testing and 650 were tested. Seventy-two individuals carried at least one LRRK2 G2019S mutation; 38 with PD (12.5%) and 34 without (10.1%). Among the AJ PD participants, each affected first-degree relative increased the likelihood the individual was LRRK2+ [OR = 4.7; 95% confidence interval = (2.4–9.0)]. The same was not observed among the unaffected AJ subjects (P = 0.11). An internet-based approach successfully screened large numbers of individuals to identify those with risk factors increasing the likelihood that they carried a LRRK2 G2019S mutation. A similar approach could be implemented in other disorders to identify individuals for clinical trials, biomarker analyses and other types of research studies.Item Parkinson's disease variant detection and disclosure: PD GENEration, a North American study(Oxford University Press, 2024) Cook, Lola; Verbrugge, Jennifer; Schwantes-An, Tae-Hwi; Schulze, Jeanine; Foroud, Tatiana; Hall, Anne; Marder, Karen S.; Mata, Ignacio F.; Mencacci, Niccolò E.; Nance, Martha A.; Schwarzschild, Michael A.; Simuni, Tanya; Bressman, Susan; Wills, Anne-Marie; Fernandez, Hubert H.; Litvan, Irene; Lyons, Kelly E.; Shill, Holly A.; Singer, Carlos; Tropea, Thomas F.; Vanegas Arroyave, Nora; Carbonell, Janfreisy; Cruz Vicioso, Rossy; Katus, Linn; Quinn, Joseph F.; Hodges, Priscila D.; Meng, Yan; Strom, Samuel P.; Blauwendraat, Cornelis; Lohmann, Katja; Casaceli, Cynthia; Rao, Shilpa C.; Ghosh Galvelis, Kamalini; Naito, Anna; Beck, James C.; Alcalay, Roy N.; Medical and Molecular Genetics, School of MedicineVariants in seven genes (LRRK2, GBA1, PRKN, SNCA, PINK1, PARK7 and VPS35) have been formally adjudicated as causal contributors to Parkinson's disease; however, individuals with Parkinson's disease are often unaware of their genetic status since clinical testing is infrequently offered. As a result, genetic information is not incorporated into clinical care, and variant-targeted precision medicine trials struggle to enrol people with Parkinson's disease. Understanding the yield of genetic testing using an established gene panel in a large, geographically diverse North American population would help patients, clinicians, clinical researchers, laboratories and insurers better understand the importance of genetics in approaching Parkinson's disease. PD GENEration is an ongoing multi-centre, observational study (NCT04057794, NCT04994015) offering genetic testing with results disclosure and genetic counselling to those in the US (including Puerto Rico), Canada and the Dominican Republic, through local clinical sites or remotely through self-enrolment. DNA samples are analysed by next-generation sequencing including deletion/duplication analysis (Fulgent Genetics) with targeted testing of seven major Parkinson's disease-related genes. Variants classified as pathogenic/likely pathogenic/risk variants are disclosed to all tested participants by either neurologists or genetic counsellors. Demographic and clinical features are collected at baseline visits. Between September 2019 and June 2023, the study enrolled 10 510 participants across >85 centres, with 8301 having received results. Participants were: 59% male; 86% White, 2% Asian, 4% Black/African American, 9% Hispanic/Latino; mean age 67.4 ± 10.8 years. Reportable genetic variants were observed in 13% of all participants, including 18% of participants with one or more 'high risk factors' for a genetic aetiology: early onset (<50 years), high-risk ancestry (Ashkenazi Jewish/Basque/North African Berber), an affected first-degree relative; and, importantly, in 9.1% of people with none of these risk factors. Reportable variants in GBA1 were identified in 7.7% of all participants; 2.4% in LRRK2; 2.1% in PRKN; 0.1% in SNCA; and 0.2% in PINK1, PARK7 or VPS35 combined. Variants in more than one of the seven genes were identified in 0.4% of participants. Approximately 13% of study participants had a reportable genetic variant, with a 9% yield in people with no high-risk factors. This supports the promotion of universal access to genetic testing for Parkinson's disease, as well as therapeutic trials for GBA1 and LRRK2-related Parkinson's disease.Item Relevance of genetic testing in the gene-targeted trial era: the Rostock Parkinson's disease study(Oxford University Press, 2024) Westenberger, Ana; Skrahina, Volha; Usnich, Tatiana; Beetz, Christian; Vollstedt, Eva-Juliane; Laabs, Björn-Hergen; Paul, Jefri J.; Curado, Filipa; Skobalj, Snezana; Gaber, Hanaa; Olmedillas, Maria; Bogdanovic, Xenia; Ameziane, Najim; Schell, Nathalie; Aasly, Jan Olav; Afshari, Mitra; Agarwal, Pinky; Aldred, Jason; Alonso-Frech, Fernando; Anderson, Roderick; Araújo, Rui; Arkadir, David; Avenali, Micol; Balal, Mehmet; Benizri, Sandra; Bette, Sagari; Bhatia, Perminder; Bonello, Michael; Braga-Neto, Pedro; Brauneis, Sarah; Costa Cardoso, Francisco Eduardo; Cavallieri, Francesco; Classen, Joseph; Cohen, Lisa; Coletta, Della; Crosiers, David; Cullufi, Paskal; Dashtipour, Khashayar; Demirkiran, Meltem; de Carvalho Aguiar, Patricia; De Rosa, Anna; Djaldetti, Ruth; Dogu, Okan; Dos Santos Ghilardi, Maria Gabriela; Eggers, Carsten; Elibol, Bulent; Ellenbogen, Aaron; Ertan, Sibel; Fabiani, Giorgio; Falkenburger, Björn H.; Farrow, Simon; Fay-Karmon, Tsviya; Ferencz, Gerald J.; Fonoff, Erich Talamoni; Fragoso, Yara Dadalti; Genç, Gençer; Gorospe, Arantza; Grandas, Francisco; Gruber, Doreen; Gudesblatt, Mark; Gurevich, Tanya; Hagenah, Johann; Hanagasi, Hasmet A.; Hassin-Baer, Sharon; Hauser, Robert A.; Hernández-Vara, Jorge; Herting, Birgit; Hinson, Vanessa K.; Hogg, Elliot; Hu, Michele T.; Hummelgen, Eduardo; Hussey, Kelly; Infante, Jon; Isaacson, Stuart H.; Jauma, Serge; Koleva-Alazeh, Natalia; Kuhlenbäumer, Gregor; Kühn, Andrea; Litvan, Irene; López-Manzanares, Lydia; Luxmore, McKenzie; Manandhar, Sujeena; Marcaud, Veronique; Markopoulou, Katerina; Marras, Connie; McKenzie, Mark; Matarazzo, Michele; Merello, Marcelo; Mollenhauer, Brit; Morgan, John C.; Mullin, Stephen; Musacchio, Thomas; Myers, Bennett; Negrotti, Anna; Nieves, Anette; Nitsan, Zeev; Oskooilar, Nader; Öztop-Çakmak, Özgür; Pal, Gian; Pavese, Nicola; Percesepe, Antonio; Piccoli, Tommaso; Pinto de Souza, Carolina; Prell, Tino; Pulera, Mark; Raw, Jason; Reetz, Kathrin; Reiner, Johnathan; Rosenberg, David; Ruiz-Lopez, Marta; Ruiz Martinez, Javier; Sammler, Esther; Santos-Lobato, Bruno Lopes; Saunders-Pullman, Rachel; Schlesinger, Ilana; Schofield, Christine M.; Schumacher-Schuh, Artur F.; Scott, Burton; Sesar, Ángel; Shafer, Stuart J.; Sheridan, Ray; Silverdale, Monty; Sophia, Rani; Spitz, Mariana; Stathis, Pantelis; Stocchi, Fabrizio; Tagliati, Michele; Tai, Yen F.; Terwecoren, Annelies; Thonke, Sven; Tönges, Lars; Toschi, Giulia; Tumas, Vitor; Urban, Peter Paul; Vacca, Laura; Vandenberghe, Wim; Valente, Enza Maria; Valzania, Franco; Vela-Desojo, Lydia; Weill, Caroline; Weise, David; Wojcieszek, Joanne; Wolz, Martin; Yahalom, Gilad; Yalcin-Cakmakli, Gul; Zittel, Simone; Zlotnik, Yair; Kandaswamy, Krishna K.; Balck, Alexander; Hanssen, Henrike; Borsche, Max; Lange, Lara M.; Csoti, Ilona; Lohmann, Katja; Kasten, Meike; Brüggemann, Norbert; Rolfs, Arndt; Klein, Christine; Bauer, Peter; Neurology, School of MedicineEstimates of the spectrum and frequency of pathogenic variants in Parkinson's disease (PD) in different populations are currently limited and biased. Furthermore, although therapeutic modification of several genetic targets has reached the clinical trial stage, a major obstacle in conducting these trials is that PD patients are largely unaware of their genetic status and, therefore, cannot be recruited. Expanding the number of investigated PD-related genes and including genes related to disorders with overlapping clinical features in large, well-phenotyped PD patient groups is a prerequisite for capturing the full variant spectrum underlying PD and for stratifying and prioritizing patients for gene-targeted clinical trials. The Rostock Parkinson's disease (ROPAD) study is an observational clinical study aiming to determine the frequency and spectrum of genetic variants contributing to PD in a large international cohort. We investigated variants in 50 genes with either an established relevance for PD or possible phenotypic overlap in a group of 12 580 PD patients from 16 countries [62.3% male; 92.0% White; 27.0% positive family history (FH+), median age at onset (AAO) 59 years] using a next-generation sequencing panel. Altogether, in 1864 (14.8%) ROPAD participants (58.1% male; 91.0% White, 35.5% FH+, median AAO 55 years), a PD-relevant genetic test (PDGT) was positive based on GBA1 risk variants (10.4%) or pathogenic/likely pathogenic variants in LRRK2 (2.9%), PRKN (0.9%), SNCA (0.2%) or PINK1 (0.1%) or a combination of two genetic findings in two genes (∼0.2%). Of note, the adjusted positive PDGT fraction, i.e. the fraction of positive PDGTs per country weighted by the fraction of the population of the world that they represent, was 14.5%. Positive PDGTs were identified in 19.9% of patients with an AAO ≤ 50 years, in 19.5% of patients with FH+ and in 26.9% with an AAO ≤ 50 years and FH+. In comparison to the idiopathic PD group (6846 patients with benign variants), the positive PDGT group had a significantly lower AAO (4 years, P = 9 × 10-34). The probability of a positive PDGT decreased by 3% with every additional AAO year (P = 1 × 10-35). Female patients were 22% more likely to have a positive PDGT (P = 3 × 10-4), and for individuals with FH+ this likelihood was 55% higher (P = 1 × 10-14). About 0.8% of the ROPAD participants had positive genetic testing findings in parkinsonism-, dystonia/dyskinesia- or dementia-related genes. In the emerging era of gene-targeted PD clinical trials, our finding that ∼15% of patients harbour potentially actionable genetic variants offers an important prospect to affected individuals and their families and underlines the need for genetic testing in PD patients. Thus, the insights from the ROPAD study allow for data-driven, differential genetic counselling across the spectrum of different AAOs and family histories and promote a possible policy change in the application of genetic testing as a routine part of patient evaluation and care in PD.Item A revised 1.6 Å structure of the GTPase domain of the Parkinson’s disease-associated protein LRRK2 provides insights into mechanisms(Cold Spring Harbor Laboratory Press, 2019) Wu, Chun-Xiang; Liao, Jingling; Park, Yangshin; Hoang, Neo C.; Engel, Victoria A.; Wan, Li; Oh, Misook; Sanishvili, Ruslan; Takagi, Yuichiro; Johnson, Steven M.; Wang, Mu; Federici, Mark; Nichols, R. Jeremy; Beilina, Alexandra; Reed, Xylena; Cookson, Mark R.; Hoang, Quyen Q.; Biochemistry and Molecular Biology, School of MedicineLeucine-rich repeat kinase 2 (LRRK2) is a large 286 kDa multi-domain protein whose mutation is a common cause of Parkinson’s disease (PD). One of the common sites of familial PD-associated mutations occurs at residue Arg-1441 in the GTPase domain of LRRK2. Previously, we reported that the PD-associated mutation R1441H impairs the catalytic activity of the GTPase domain thereby traps it in a persistently "on" state. More recently, we reported that the GTPase domain of LRRK2 exists in a dynamic dimer-monomer equilibrium where GTP binding shifts it to the monomeric conformation while GDP binding shifts it back to the dimeric state. We also reported that all of the PD-associated mutations at Arg-1441, including R1441H, R1441C, and R1441G, impair the nucleotide-dependent dimer-monomer conformational dynamics of the GTPase domain. However, the mechanism of this nucleotide-dependent conformational dynamics and how it is impaired by the mutations at residue Arg-1441 remained unclear. Here, we report a 1.6 Å crystal structure of the GTPase domain of LRRK2. Our structure has revealed a dynamic switch region that can be differentially regulated by GTP and GDP binding. This nucleotide-dependent regulation is impaired when residue Arg-1441 is substituted with the PD-associated mutations due to the loss of its exquisite interactions consisting of two hydrogen bonds and a π-stacking interaction at the dimer interface.Item Roco Proteins and the Parkinson's Disease-Associated LRRK2(MDPI, 2018-12-17) Liao, Jingling; Hoang, Quyen Q.; Biochemistry and Molecular Biology, School of MedicineSmall G-proteins are structurally-conserved modules that function as molecular on-off switches. They function in many different cellular processes with differential specificity determined by the unique effector-binding surfaces, which undergo conformational changes during the switching action. These switches are typically standalone monomeric modules that form transient heterodimers with specific effector proteins in the ‘on’ state, and cycle to back to the monomeric conformation in the ‘off’ state. A new class of small G-proteins called “Roco” was discovered about a decade ago; this class is distinct from the typical G-proteins in several intriguing ways. Their switch module resides within a polypeptide chain of a large multi-domain protein, always adjacent to a unique domain called COR, and its effector kinase often resides within the same polypeptide. As such, the mechanisms of action of the Roco G-proteins are likely to differ from those of the typical G-proteins. Understanding these mechanisms is important because aberrant activity in the human Roco protein LRRK2 is associated with the pathogenesis of Parkinson’s disease. This review provides an update on the current state of our understanding of the Roco G-proteins and the prospects of targeting them for therapeutic purposes.