Figure 7

A high amino acid medium activates cyclin D2 and suppresses p27 via ErbB3 to promote cell cycle.A, Western blot analysis of selected cell cycle regulators in WT αTC1-6 cells cultured in control medium or medium with high amino acids for 2-h increments. B, Western blot analysis of selected cell cycle regulators in Erbb3 KO cultured in control medium or medium with high amino acids for 2-h increments. C–F, the representative images (C) and quantification of cyclin D2 (D), CDK6 (E), and p27 (F) levels in WT αTC1-6 cells cultured in the control medium or medium with high amino acids for 24 h in the presence or absence of 30 nM rapamycin and/or 1 μM Stattic. n = 3, and the relative protein level was analyzed using one-way ANOVA with a Bonferroni post hoc test. Data are presented as mean ± SD. ∗ p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001, and ∗∗∗∗p < 0.0001. G–I, violin and t-distributed stochastic neighbor embedding plots showed the expression level and distribution of cyclin D2 (G), CDK6 (H), and p27 (I) in WT and Gcgr^−/− mouse α cells from our single-cell RNA-seq (GSE253271). CDK, cyclin dependent kinase; GCGR, glucagon receptor.