This entry includes the heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1), a nuclear factor that binds to Pol II transcripts. The family of hnRNP proteins is involved in numerous RNA-related activities []. hnRNPA1 is involved in the packaging of pre-mRNA into hnRNP particles, transport of poly(A) mRNA from the nucleus to the cytoplasm and modulation of splice site selection []. hnRNPA1 plays a role in the splicing of pyruvate kinase PKM by binding repressively to sequences flanking PKM exon 9, inhibiting exon 9 inclusion and resulting in exon 10 inclusion and production of the PKM M2 isoform []. This protein binds to the IRES and inhibits the translation of the apoptosis protease activating factor APAF1. During Enterovirus 71 (EV71) infection, APAF1 expression is essential for virus-induced apoptosis and viral particle release [].hnRNPA1 consists of two RNA recognition motifs (RRM1 and RRM2) followed by an unstructured low complexity (LC) C-terminal domain, represented in this entry [, , ]. This domain, shared by hnRNPA1 and hnRNPA2/B1, can mediate protein-protein and protein-RNA interactions and it is involved in amyloid aggregation, leading to neurodegenerative diseases including amyotrophic lateral sclerosis (ALS) and multisystem proteinopathy (MSP) [, ].
