Protein-RNA Networks Regulated by Normal and ALS-Associated Mutant HNRNPA2B1 in the Nervous System
July 10, 2015
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 approximately 2,500 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.
Martinez, F. J.; Pratt, G. A.; Van Nostrand, E. L.; Batra, R.; Huelga, S. C.; Kapeli, K.; Freese, P.; Chun, S. J.; Ling, K.; Gelboin-Burkhart, C.; Fijany, L.; Wang, H. C.; Nussbacher, J. K.; Broski, S. M.; Kim, H. J.; Lardelli, R.; Sundararaman, B.; Donohue, J. P.; Javaherian, A.; Lykke-Andersen, J.; Finkbeiner, S.; Bennett, C. F.; Ares, M., Jr.; Burge, C. B.; Taylor, J. P.; Rigo, F.; Yeo, G. W.