Calcium-dependent stress maintenance without myosin phosphorylation in skinned smooth muscle

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Science  29 Jul 1983:
Vol. 221, Issue 4609, pp. 464-466
DOI: 10.1126/science.6867722


Stress development depended on calcium-stimulated myosin phosphorylation in an arterial smooth muscle preparation in which the concentration of calcium was controlled. However, developed stress was maintained at a concentration of calcium that did not support phosphorylation. These results, in conjunction with other evidence, suggest that the interaction of two regulatory mechanisms with different calcium sensitivities regulate both stress and the rate and energetics of contraction.