Research Article Muscle-Type Specific Autophosphorylation of CaMKII Isoforms after Paced Contractions

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. We explored to what extent isoforms of the regulator of excitation-contraction and excitation-transcription coupling, cal-cium/calmodulin protein kinase II (CaMKII) contribute to the specificity of myocellular calcium sensing betweenmuscle types and whether concentration transients in its autophosphorylation can be simulated. CaMKII autophosphorylation atThr287was assessed in three muscle compartments of the rat after slow or fast motor unit-type stimulation and was compared against a computational model (CaMuZclE) coupling myocellular calcium dynamics with CaMKIIThr287 phosphorylation. Qualitative differences existed between fast- (gastrocnemius medialis) and slow-type muscle (soleus) for the expression pattern of CaMKII isoforms. Phospho-Thr287 content o