HnRNPA2B1 encodes an RNA binding protein associated with neurodegeneration. However, its function in the nervous system is unclear. Transcriptome-wide crosslinking and immunoprecipitation in mouse spinal cord discover UAGG motifs enriched within â¼2,500 hnRNP A2/B1 binding sites and an unexpected role for hnRNP A2/B1 in alternative polyadenylation. HnRNP A2/B1 loss results in alternative splicing (AS), including skipping of an exon in amyotrophic lateral sclerosis (ALS)-associated D-amino acid oxidase (DAO) that reduces D-serine metabolism. ALS-associated hnRNP A2/B1 D290V mutant patient fibroblasts and motor neurons differentiated from induced pluripotent stem cells (iPSC-MNs) demonstrate abnormal splicing changes, likely due to increased nuclear-insoluble hnRNP A2/B1. Mutant iPSC-MNs display decreased survival in long-term culture and exhibit hnRNP A2/B1 localization to cytoplasmic granules as well as exacerbated changes in gene expression and splicing upon cellular stress. Our findings provide a cellular resource and reveal RNA networks relevant to neurodegeneration, regulated by normal and mutant hnRNP A2/B1. VIDEO ABSTRACT.
Alternative Splicing/genetics , Amyotrophic Lateral Sclerosis/genetics , Cell Survival/genetics , Fibroblasts/metabolism , Heterogeneous-Nuclear Ribonucleoprotein Group A-B/genetics , Motor Neurons/metabolism , Protein Transport/genetics , Amyotrophic Lateral Sclerosis/metabolism , Animals , Case-Control Studies , D-Amino-Acid Oxidase/genetics , D-Amino-Acid Oxidase/metabolism , Fluorescent Antibody Technique , Gene Expression , Gene Expression Profiling , Heterogeneous-Nuclear Ribonucleoprotein Group A-B/metabolism , Humans , Induced Pluripotent Stem Cells , Mice , Mutation , Polyadenylation
