Smooth muscle contraction due to release of calcium, occurs because of ?
In Smooth muscles, rise in intracellular leads to binding of 4 Ca++ ions with calmodulin. Calcium-calmodulin complex then activates myosin light chain kinase (MLCK). MLCK phosphorylates the regulatory light chain of myosin; this phosphorylation then leads to interaction of myosin with actin. Calmodulin is structurally and functionally related to troponin. Troponin is present in skeletal muscles and initiates contraction by causing a conformational change in the tropomyosin molecule which then uncovers the active sites on the actin filament.
Increased cAMP
Calcium combining with troponin C
Increased cGMP
Calmodulin-dependant myosin light chain kinase
Smooth Muscle