Muscarinic regulation of hnRNPA2/B1 translation. A, B, Representative immunofluorescence images (A) and Western blots (B) with quantification of hnRNPA2/B1 protein levels in primary hippocampal neurons after treatment with carbachol for 48 h. hnRNPA2/B1 expression was normalized to actin (n = 3). C, Representative Western blot and quantification of hnRNPA2/B1 expression in primary hippocampal neurons after treatment with carbachol, mecamylamine (meca.), and atropine. hnRNPA2/B1 expression was normalized to actin (n = 4). The values plotted are averaged from the gels of each individual experiment. D, Representative Western blot and quantification of hnRNPA2/B1 expression in hippocampal tissue of M4 muscarinic knock-out mice (M4-KO; n = 7) and M1 receptor knock-out mice (M1-KO; control, n = 7; M1-KO mice, n = 8). E, M1 muscarinic receptor agonist AF102B significantly increased hnRNPA2/B1 protein levels in primary hippocampal cultures (n = 5). F, Increased expression of the full-length hnRNPA2/B1 transcripts of cells treated with carbachol is blocked by the administration of atropine (n = 5). G, Proposed model wherein muscarinic M1 receptors signaling would shift the ratio of hnRNPA2/B transcripts, favoring the full length transcripts, and therefore increase translation of the protein. Data are mean ± SEM. *p < 0.05.