Dephosphorylation second messenger systems

Mechanism involves inhibition of the dephosphorylation of both IP2 to IP , and IP to IP, necessary steps in the recycling of inositol — A PIP2. This second messenger system is involved in receptor interactions involving ACh, NE, and 5HT. Lithium may also cause A cAMP —>A in its function as a second messenger (renal V2 receptors are coupled to cAMP see below). 

The arachidonic acid cascade takes part in a large number of functional interactions with other intracellular second messenger systems. As one would expect from their universal regulatory functions in the physiology of mammalian cells, protein phosphorylation and dephosphorylation play a major part in modulating arachidonate mobilization. Two multifunctional (and ubiquitous) protein kinases, PKC and PKA, have been studied extensively in this regard. 

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