Myosin light chain kinase is phosphorylated in smooth muscle cells in response to nitric oxide signaling resulting in
A) smooth muscle relaxation and blood vessel dilation
B) smooth muscle contraction and blood vessel dilation
C) smooth muscle relaxation and blood vessel constriction
D) smooth muscle contraction and blood vessel constriction

Question

Quizplus · Accepted Answer

Phosphorylation of myosin light chain kinase in smooth muscle cells in response to nitric oxide signaling leads to smooth muscle relaxation and blood vessel dilation. Nitric oxide stimulates the production of cyclic GMP, which activates protein kinase G (PKG). PKG in turn phosphorylates myosin light chain kinase, leading to a decrease in the amount of active myosin light chain kinase and a decrease in smooth muscle contraction. This results in blood vessel dilation and increased blood flow.

Myosin Light Chain Kinase Is Phosphorylated in Smooth Muscle Cells