Role of MAST3 kinase in developmental and epileptic encephalopathy

MAST3 激酶在发育性脑病和癫痫性脑病中的作用

• 批准号: 10217382
• 负责人: ANGUS C. NAIRN
• 金额: $ 14.7万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-15 至 2023-04-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10217382
• 关键词: Acids; Address; Affect; Affinity Chromatography; Antibodies; Area; Biochemical; Biological; Biological Assay; Brain; Cell physiology; Cells; Cerebral Palsy; Cerebral cortex; Child; Childhood; Congenital cerebellar hypoplasia; Corpus Callosum; Corpus striatum structure; Cortical Malformation; Country; Data; Development; Developmental Delay Disorders; Developmental Therapeutics Program; Diagnosis; Diagnostic; Disease; Electrophysiology (science); Epilepsy; Family; Genes; Genetic Diseases; Genetic Research; Goals; Hippocampus (Brain); In Vitro; Income; Individual; Infection; Injury; Intellectual functioning disability; Intervention; Lead; Lentivirus Vector; Life; Link; Mass Spectrum Analysis; Microtubules; Missense Mutation; Modeling; Molecular; Morphology; Mutation; Neuraxis; Neurologic; Neurons; Pathogenesis; Patients; Pharmaceutical Preparations; Phenotype; Phosphorylation; Phosphotransferases; Physiological; Play; Prevalence; Promega; Property; Protein Phosphatase 2A Regulatory Subunit PR53; Protein Serine/Threonine Phosphatase; Protein phosphatase; Protein-Serine-Threonine Kinases; Proteins; Quality of life; Recombinant Proteins; Recombinants; Research; Rett Syndrome; Risk; Role; Signal Transduction; Syndrome; Techniques; Testing; United States; Variant; Vertebral column; childhood epilepsy; cyclic AMP-regulated phosphoprotein 16; epileptic encephalopathies; experimental study; gain of function; health care quality; improved; inhibitor/antagonist; knock-down; loss of function mutation; low and middle-income countries; mental development; mutant; nervous system disorder; neuron development; novel diagnostics; novel therapeutics; targeted treatment; tool

Epilepsy is one of the most common neurological disorders globally, estimated to affect 3.4 million people in the United States and 50 million people globally. Alarmingly, even in high-income countries, epilepsy in one- third of patients resists conventional drug intervention, highlighting the need to further understand the pathogenesis and molecular changes associated with this disease. Developmental and epileptic encephalopathy (DEE) is a relatively new concept in epilepsy research that describes genetic disorders in which a variation in a gene, such as a mutation, causes increased epileptiform activity and slowing of mental development. Recently, several developmental neurological conditions, such as Rett syndrome, cerebral palsy, and mega-corpus-callosum syndrome with cerebellar hypoplasia and cortical malformations have been associated with mutations in the microtubule-associated serine/threonine (MAST) protein kinase family. Specifically, our colleagues have discovered seven individuals with DEE with de novo missense mutations in the MAST3 gene: G510S, G515S, L516P, and V551L. Our group recently showed in brain that MAST3 phosphorylates ARPP-16, a small heat- and acid-stable protein enriched in striatum and cortex, at Ser46, converting it into a potent inhibitor of the serine/threonine phosphatase PP2A. Preliminary results suggest the DEE mutations in MAST3 cause a gain-of-function increase in MAST3 activity, promoting ARPP-16 phosphorylation at Ser46 which would lead to subsequent inhibition of specific forms of PP2A. Interestingly, other recent studies have identified loss of function mutations in the catalytic C, and substrate targeting B subunits, of PP2A in individuals with intellectual disability and developmental delay, the majority of which also have epilepsy. We hypothesize that increased MAST3 activity, and selective perturbation of PP2A signaling, may in part play a causative role in the development of childhood neurological conditions. The proposed research contains two specific aims to test the hypothesis that the DEE MAST3 mutations increase kinase activity and may change its interactome, causing detrimental changes in neuronal development. Aim 1 will determine which proteins and substrates interact with MAST3, how this interactome changes when the DEE MAST3 mutations are introduced, and how this affects kinase activity. This aim will be achieved using in vitro biochemical techniques, such as kinase assays with recombinant proteins, and pulldown assays in primary neuron cultures to identify interacting proteins and substrates. Aim 2 will investigate the role of the DEE MAST3 mutations in neuronal development and function using primary neuron cultures to visualize dendritic arborization and spines, morphological changes, and electrophysiological properties. Results gained from this study will further elucidate the potential for MAST3 to be a prominent force in the development of several neurological conditions early in life. Understanding this mechanism should lead to new diagnostic tools and interventions aimed at improving the quality of life of individuals affected by these disorders.

癫痫是全球最常见的神经系统疾病之一，估计全球有340万人受其影响