Regulation of Myosin Phosphatase by a Specific Interaction with cGMP- Dependent Protein Kinase Iα

+ See all authors and affiliations

Science  19 Nov 1999:
Vol. 286, Issue 5444, pp. 1583-1587
DOI: 10.1126/science.286.5444.1583

You are currently viewing the abstract.

View Full Text


Contraction and relaxation of smooth muscle are regulated by myosin light-chain kinase and myosin phosphatase through phosphorylation and dephosphorylation of myosin light chains. Cyclic guanosine monophosphate (cGMP)–dependent protein kinase Iα (cGKIα) mediates physiologic relaxation of vascular smooth muscle in response to nitric oxide and cGMP. It is shown here that cGKIα is targeted to the smooth muscle cell contractile apparatus by a leucine zipper interaction with the myosin-binding subunit (MBS) of myosin phosphatase. Uncoupling of the cGKIα-MBS interaction prevents cGMP-dependent dephosphorylation of myosin light chain, demonstrating that this interaction is essential to the regulation of vascular smooth muscle cell tone.

  • * To whom correspondence should be addressed. E-mail: mmendelsohn{at}

View Full Text

Related Content