Effect of amino acids and insulin on components of ubiquitin-proteasome pathway. Experimental procedure is the same as described under Figure 2 except that instead of L[ring -3, 5-3H]-tyrosine cold tyrosine was used to simulate similar conditions. Values are means ± SEM for 3–4 experiments performed in triplicates. * Indicates differences in protein degradation between 0.2 × PC AA (filled bars) & 1.0 × PC AA (open bars) treatments while ψ represents differences between insulin versus control (without insulin) groups. Autoradiographic signals were normalised for GAPDH expression. In case of 14-kDa E2, autoradiographic signals for 1.2 kb transcript were normalised. Mean normalised levels of gene expression are represented as arbitrary units.