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Calmodulin Function!

5K views 1 reply 2 participants last post by  Hope2Pass 
#1 ·
hey guys
this may be a totally stupid question
but what is the action of calmodulin?
I always thought calcium bound to it in smooth muscle and then calmodulin activated myosin light chain kinase--->muscle contraction eventually

But UW says calmodulin binds and activates plasma membrane Ca-ATPase, which removes Ca from the cell by hydrolyzing ATP.

I'm so confused now:toosad: Does it do both?
 
#2 ·
I got some information from an online source. Basically, Calcium regulates its concentration through indirect negative feedback. If you click on the source link below you can read up on it in more detail.

Ca2+-ATPase is responsible for extracting calcium from the cytoplasm. An increase in intracellular calcium activates binding to calmodulin which then activates Ca2+-ATPase. This in turn causes calcium to be released from the cytoplasm. This activity establishes a method of maintaining a low level of intracellular calcium through self-regulation. Calcium, therefore, has the ability to regulate its own cellular concentration with the help of calmodulin.

Source-
http://www.cs.stedwards.edu/chem/Chemistry/CHEM43/CHEM43/Calmodulin/FUNCTION.HTML
 
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