1. hnRNPDL Phase Separation Is Regulated by Alternative Splicing and Disease-Causing Mutations Accelerate Its Aggregation
- Author
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Xavier Salvatella, Cristina Batlle, J. Paul Taylor, Elzbieta Szulc, Mireia Pesarrodona, James Messing, Maura Coughlin, Peiguo Yang, Hong Joo Kim, and Salvador Ventura
- Subjects
0301 basic medicine ,Cytoplasm ,LGMD1G ,medicine.disease_cause ,Gene Knockout Techniques ,0302 clinical medicine ,Protein Isoforms ,Disease ,hnRNPDL ,Heterogeneous-Nuclear Ribonucleoprotein D ,Muscular dystrophy ,lcsh:QH301-705.5 ,Prion-like ,Ribonucleoprotein ,prion-like ,Mutation ,Chemistry ,aggregation ,amyloid ,Hnrnpdl ,Cell biology ,RNA splicing ,Dactinomycin ,Drosophila ,Gene isoform ,Amyloid ,Phase separation ,Amyloidogenic Proteins ,Protein Aggregation, Pathological ,Article ,General Biochemistry, Genetics and Molecular Biology ,alternative splicing ,Aggregation ,03 medical and health sciences ,Microscopy, Electron, Transmission ,Organelle ,medicine ,Animals ,Humans ,Cell Nucleus ,Muscle Cells ,disease ,Alternative splicing ,isoforms ,medicine.disease ,Kinetics ,030104 developmental biology ,lcsh:Biology (General) ,Muscular Dystrophies, Limb-Girdle ,phase separation ,Isoforms ,030217 neurology & neurosurgery ,HeLa Cells - Abstract
Summary Prion-like proteins form multivalent assemblies and phase separate into membraneless organelles. Heterogeneous ribonucleoprotein D-like (hnRNPDL) is a RNA-processing prion-like protein with three alternative splicing (AS) isoforms, which lack none, one, or both of its two disordered domains. It has been suggested that AS might regulate the assembly properties of RNA-processing proteins by controlling the incorporation of multivalent disordered regions in the isoforms. This, in turn, would modulate their activity in the downstream splicing program. Here, we demonstrate that AS controls the phase separation of hnRNPDL, as well as the size and dynamics of its nuclear complexes, its nucleus-cytoplasm shuttling, and amyloidogenicity. Mutation of the highly conserved D378 in the disordered C-terminal prion-like domain of hnRNPDL causes limb-girdle muscular dystrophy 1G. We show that D378H/N disease mutations impact hnRNPDL assembly properties, accelerating aggregation and dramatically reducing the protein solubility in the muscle of Drosophila, suggesting a genetic loss-of-function mechanism for this muscular disorder., Graphical Abstract, Highlights • hnRNPDL requires both N- and C-terminal IDRs to phase separate • The absence of N-terminal IDR facilitates aggregation • The unique combination of IDRs in each isoform determines its cellular behavior • D378N/H mutations accelerate hnRNPDL aggregation and compromise its solubility, Batlle et al. show that alternative splicing controls heterogeneous ribonucleoprotein D-like (hnRNPDL) phase separation, aggregation, and solubility. Mutations that cause LGMD1G accelerate hnRNPDL aggregation and promote insolubility in Drosophila.
- Published
- 2020
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