[en] [en] OBJECTIVE: Variants in human PRRT2 cause paroxysmal kinesigenic dyskinesia (PKD) and other neurological disorders. Most reported variants resulting in truncating proteins failed to localize to cytoplasmic membrane. The present study identifies novel PRRT2 variants in PKD and epilepsy patients and evaluates the functional consequences of PRRT2 missense variations.
METHODS: We investigated two families with PKD and epilepsies using Sanger sequencing and a multiple gene panel. Subcellular localization of mutant proteins was investigated using confocal microscopy and cell surface biotinylation assay in Prrt2-transfected cells.
RESULTS: Two novel PRRT2 variants, p.His232Glnfs*10 and p.Leu298Pro, were identified, and functional study revealed impaired localization of both mutant proteins to the plasma membrane. Further investigation of other reported missense variants revealed decreased protein targeting to the plasma membrane in eight of the 13 missense variants examined (p.Trp281Arg, p.Ala287Thr, p.Ala291Val, p.Arg295Gln, p.Leu298Pro, p.Ala306Asp, p.Gly324Glu, and p.Gly324Arg). In contrast, all benign variants we tested exhibited predominant localization to the plasma membrane similar to wild-type Prrt2. Most likely pathogenic variants were located at conserved amino acid residues near the C-terminus, whereas truncating variants spread throughout the gene.
SIGNIFICANCE: PRRT2 missense variants clustering at the C-terminus often lead to protein mislocalization. Failure in protein targeting to the plasma membrane by PRRT2 variants may be a key mechanism in causing PKD and related neurological disorders.
Disciplines :
Genetics & genetic processes
Author, co-author :
Tsai, Meng-Han ✱; Department of Neurology, College of Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University, Kaohsiung, Taiwan
Nian, Fang-Shin ✱; Université de Liège - ULiège > GIGA > GIGA Neurosciences - Molecular Regulation of Neurogenesis ; Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan ; Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei, Taiwan
Hsu, Mei-Hsin; Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
Liu, Wei-Szu; Department of Life Sciences, National Yang-Ming University, Taipei, Taiwan
Liu, Yo-Tsen; Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan ; Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan ; Department of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan ; Brain Research Center, National Yang-Ming University, Taipei, Taiwan
Liu, Chen; Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan
Lin, Po-Hsi; Department of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan
Hwang, Daw-Yang; Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
Chuang, Yao-Chung; Department of Neurology, College of Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University, Kaohsiung, Taiwan
Tsai, Jin-Wu ; Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan ; Brain Research Center, National Yang-Ming University, Taipei, Taiwan ; Biophotonics and Molecular Imaging Research Center, National Yang-Ming University, Taipei, Taiwan
✱ These authors have contributed equally to this work.
Language :
English
Title :
PRRT2 missense mutations cluster near C-terminus and frequently lead to protein mislocalization.
UST - University System of Taiwan Taipei Veterans General Hospital NIHR - National Institute for Health Research Academia Sinica
Funding text :
Funding information Chang Gung Medical Foundation (CMRPG8G0251, CMRPG8G1411) and Ministry of Science and Technology, Taiwan (MOST103-2314-B-182A-025-MY2, 105-2314-B-182A-124, 106-2314-B-182A-077, 107-2314-B-182A-057 -MY3) to M.-H.T. Ministry of Science and Technology, Taiwan (105-2314-B-075 -066), National Health Research Institutes (NHRI-EX107-10507EC), Taipei Veterans General Hospital-University System of Taiwan (VGHUST106-G7-5-1), and Taipei Veterans General Hospital (V106C-153) to Y.-T.L. The Ministry of Science and Technology (102-2314-B-075-079, 103-2628-B-010-002-MY3, 104-2633-H-010-001, 104-2745-B-075-001, 105-2633-B-009-003, 106-2321-B-075-001, 106-2628-B-010-002-MY3, 107-2628-B-010-002-MY3, 107-2221-E-010-014, 107-2321-B-075-001), Taipei Veterans General Hospital-University System of Taiwan (VGHUST106-G7-5-2), National Health Research Institutes (NHRI-EX103-10314NC), Academia Sinica (AS-104-TP-B09 and 2396-105-0100), National Yang-Ming University School of Medicine (Development and Construction Plan 107F-M01-0502), and Brain Research Center, National Yang-Ming University through the Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education to J.-W.T. We thank the patients and their families for participating in this study; the Genomic and Proteomic Core Laboratory and the Biobank, Department of Medical Research, Kaohsiung Chang Gung Memorial Hospital, and the Instrumentation Resource Center, National Yang-Ming University, for technical support; and the Whole-Genome Research Core Laboratory of Human Disease, Keelung Chang Gung Memorial Hospital, for providing the Taiwanese control data.010-014, 107-2321-B-075-001), Taipei Veterans General Hospital-University System of Taiwan (VGHUST106-G7-5-2), National Health Research Institutes (NHRI-EX103-10314NC), Academia Sinica (AS-104-TP-B09 and 2396-105-0100), National Yang-Ming University School of Medicine (Development and Construction Plan 107F-M01-0502), and Brain Research Center, National Yang-Ming University through the Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education to J.-W.T.
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