Western blot of soluble extracts of C2C12 myotubes treated with 0 (lanes 1 and 7); 1.0 (lanes 2 and 8); 2.1 (lanes 3 and 9); 4.2 (lanes 4 and 10); 10 (lanes 5 and 11) or 20 nM PIF (lanes 6 and 12) in the absence (lanes 1–6) or after 2 h pretreatment with trifluoroacetyl AA (20 μM) (lanes 7–12). Bands were detected using either antibody to 20S proteasome α-subunits (A), iPLA2 (B) or β-tubulin (C). The blots shown are representative of at least three separate experiments.
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