Proteomics Platform, Broad Institute of MIT and Harvard, Cambridge, United States
Namrata D Udeshi
Proteomics Platform, Broad Institute of MIT and Harvard, Cambridge, United States
Cadence Pearce
Proteomics Platform, Broad Institute of MIT and Harvard, Cambridge, United States
Hanjie Jiang
Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, United States; Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Boston, United States
Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, United States; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
Miroslav P Milev
Department of Biology, Concordia University of Edmonton, Montreal, Canada
Hashem A Almousa
Department of Biology, Concordia University of Edmonton, Montreal, Canada
Elyshia McNamara
Faculty of Health and Medical Sciences, Centre of Medical Research, Harry Perkins Institute of Medical Research, University of Western Australia, Perth, Australia
Jeffrey Widrick
Division of Genetics, Boston Children’s Hospital, Harvard Medical School, Boston, United States
Claudio Perez
Department of Anesthesiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, United States
Gianina Ravenscroft
Faculty of Health and Medical Sciences, Centre of Medical Research, Harry Perkins Institute of Medical Research, University of Western Australia, Perth, Australia
Michael Sacher
Department of Biology, Concordia University of Edmonton, Montreal, Canada; Department of Anatomy and Cell Biology, McGill University, Montreal, Canada
Ubiquitin-proteasome system (UPS) dysfunction is associated with the pathology of a wide range of human diseases, including myopathies and muscular atrophy. However, the mechanistic understanding of specific components of the regulation of protein turnover during development and disease progression in skeletal muscle is unclear. Mutations in KLHL40, an E3 ubiquitin ligase cullin3 (CUL3) substrate-specific adapter protein, result in severe congenital nemaline myopathy, but the events that initiate the pathology and the mechanism through which it becomes pervasive remain poorly understood. To characterize the KLHL40-regulated ubiquitin-modified proteome during skeletal muscle development and disease onset, we used global, quantitative mass spectrometry-based ubiquitylome and global proteome analyses of klhl40a mutant zebrafish during disease progression. Global proteomics during skeletal muscle development revealed extensive remodeling of functional modules linked with sarcomere formation, energy, biosynthetic metabolic processes, and vesicle trafficking. Combined analysis of klh40 mutant muscle proteome and ubiquitylome identified thin filament proteins, metabolic enzymes, and ER-Golgi vesicle trafficking pathway proteins regulated by ubiquitylation during muscle development. Our studies identified a role for KLHL40 as a regulator of ER-Golgi anterograde trafficking through ubiquitin-mediated protein degradation of secretion-associated Ras-related GTPase1a (Sar1a). In KLHL40-deficient muscle, defects in ER exit site vesicle formation and downstream transport of extracellular cargo proteins result in structural and functional abnormalities. Our work reveals that the muscle proteome is dynamically fine-tuned by ubiquitylation to regulate skeletal muscle development and uncovers new disease mechanisms for therapeutic development in patients.
