Smooth Muscle Contraction - binding protein. 3. The...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Smooth Muscle Contraction ‘Cheat Sheet’ Skeletal muscle – contraction initiated by calcium binding to troponin complex of actin. Smooth muscle – contraction initiated by calcium-regulated phosphorylation of myosin. Given: 1. Actin as in skeletal muscle, but with no troponin complex. 2. Myosin made up of heavy and light chains. 3. A myosin light-chain kinase. 4. A myosin light-chain phosphatase. Sequence: 1. Intracellular calcium is increased by one of a number of mechanisms and from either extra- or intra-cellular sources. 2. The Ca++ binds to calmodulin (CAL), a somewhat ubiquitous intracellular
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: binding protein. 3. The Ca++/CAL complex activates a myosin light-chain kinase which phosphorylates the myosin. 4. The phosphorylation of the myosin light chains then allows the myosin ATPase to function. 5. Myosin and actin bind and release energy. 6. A myosin light-chain phosphatase dephosphorylates myosin inhibiting contraction. The level of tension is determined by a balance between the Ca++ regulated phosphorylation of myosin by the kinase, and the deposphorylation by the phosphatase. The activity of the phosphatase can also be regulated....
View Full Document

Page1 / 2

Smooth Muscle Contraction - binding protein. 3. The...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online