title: GTP binding controls complex formation by the human ROCO protein MASL1.
abstract: The human ROCO proteins are a family of multi-domain proteins sharing a conserved ROC-COR supra-domain. The family has four members: leucine-rich repeat kinase 1 (LRRK1), leucine-rich repeat kinase 2 (LRRK2), death-associated protein kinase 1 (DAPK1) and malignant fibrous histiocytoma amplified sequences with leucine-rich tandem repeats 1 (MASL1). Previous studies of LRRK1/2 and DAPK1 have shown that the ROC (Ras of complex proteins) domain can bind and hydrolyse GTP, but the cellular consequences of this activity are still unclear. Here, the first biochemical characterization of MASL1 and the impact of GTP binding on MASL1 complex formation are reported. The results demonstrate that MASL1, similar to other ROCO proteins, can bind guanosine nucleotides via its ROC domain. Furthermore, MASL1 exists in two distinct cellular complexes associated with heat shock protein 60, and the formation of a low molecular weight pool of MASL1 is modulated by GTP binding. Finally, loss of GTP enhances MASL1 toxicity in cells. Taken together, these data point to a central role for the ROC/GTPase domain of MASL1 in the regulation of its cellular function.
authors.affiliation: Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK.
authors.forename: Sybille
authors.initials: S
authors.lastname: Dihanich
authors.forename: Laura
authors.initials: L
authors.lastname: Civiero
authors.forename: Claudia
authors.initials: C
authors.lastname: Manzoni
authors.forename: Adamantios
authors.initials: A
authors.lastname: Mamais
authors.forename: Rina
authors.initials: R
authors.lastname: Bandopadhyay
authors.forename: Elisa
authors.initials: E
authors.lastname: Greggio
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Lewis
mesh_terms: D018797:Cell Cycle Proteins / Q000378:metabolism*; D002470:Cell Survival; D018834:Chaperonin 60 / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005434:Flow Cytometry; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D007124:Immunoenzyme Techniques; D047468:Immunoprecipitation; D015513:Oncogene Proteins / Q000378:metabolism*; D015398:Signal Transduction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D018797:Cell Cycle Proteins; D018834:Chaperonin 60; D004268:DNA-Binding Proteins; C117302:MFHAS1 protein, human; D015513:Oncogene Proteins; D006160:Guanosine Triphosphate; D020558:GTP Phosphohydrolases
keywords: G-protein; HSP60; LRRK2; MASL1; ROCO; complex formation