Fig. 3.

Effects of roscovitine and SB415286 on CDK5 and GSK3β activity in L6 myotubes.

Wild-type L6 myotubes were incubated in EBSS containing amino acid mix at plasma physiological concentrations for 6 h in the presence/absence of 50 μM SB415286 or 30 μM roscovitine as indicated. Cell lysates were prepared and either 500 μg or 100 μg subjected to immunoprecipitation with CDK5 or GSKβ antibodies respectively. Kinase activity assays were carried out using histone H1 or phospho-GS peptide respectively as substrates. Activities are presented as the mean ± S.E.M (n = 3).