Fig. 6: eIF4EBP1 regulation coincides with ribosome abundance and controls neuronal Satb2 fate in vivo.
From: A critical period of translational control during brain development at codon resolution
a, Model of early vs late neurogenesis ribosome levels and per-codon changes in ribosome occupancy. b, Positional weight matrix of the top two motifs ranked by P value in the 5′ UTR and 3′ UTR of TE up or down mRNAs. 5′ TOP motifs are highlighted (pink square). c, Schematic portraying eIF4EBP1 inhibition of ribosomal protein mRNA 5′ TOP sequence translation. d, Western blot analysis of total and phosphorylated eIF4EBP1 levels in neocortex lysates in biological duplicate (n = 4–6 hemispheres per lane). Concurrent trajectory of Rpl and Rps translation is shown below. e,f, IHC of total (e) and phosphorylated (f) eIF4EBP1 expression in neocortex coronal sections across neurogenesis. Blood vessels (stars) are a common staining finding. g, shRNA knockdown of eIF4EBP1 compared with scrambled control by IUE at E13.5, followed by analysis at E15.5 with Satb2 protein immunolabeling. Co-electroporation of eGFP labels all transfected cells. Cortical plate (CP) boundary is demarcated (dotted line), zoom of yellow boxes (right). h, Quantification of g, n = independent electroporated brains, for the percentage of electroporated cells expressing Satb2 protein (left), and number of cells migrating into the cortical plate (right). Median (line), two-sided Mann–Whitney U-test, P < 0.05 as shown. i, Summary of timed translation changes and neuronal specification during neocortex development. See also Supplementary Table 3.
