Figure 5
Stretch response of p70S6K T389, but not S6RP, is rapamycin-sensitive in γ-SG-/-muscles. EDL muscles from C57 and γ-SG-/- mice were maintained in oxygenated high glucose DMEM supplemented with or without rapamycin and subjected to passive stretching for 90 min. (A) Representative immunoblots of P-Akt, T-Akt, P-p70S6K (T389 and T421/S424 sites), P-S6RP, and tubulin. Left panels DMEM alone; right panels DMEM + rapamycin. (B-E) Quantification of P-Akt (B), P-p70S6K T389 (C), P-p70S6K T421/S424 (D), and P-S6RP (E). Legend in B applies to all graphs. P-Akt was normalized to T-Akt; all other proteins were normalized to tubulin. n = 2-3 muscles per genotype and condition. Bars represent mean ± standard error. All datasets were tested by two-way ANOVA. For P-Akt in γ-SG-/- muscles, stretch was significant. For P-p70S6K T389 in γ-SG-/- muscles, stretch, rapamycin treatment, and the interaction between them were all significant. For P-S6RP in γ-SG-/- muscles, stretch was significant. ‡Significantly different to NS γ-SG-/- control and †significantly different to S γ-SG-/- without rapamycin by two-way ANOVA with Tukey’s multiple comparisons test. NS, non-stretched; S, stretched.