CAMP as second messenger in GPCR signal transduction

[uio]

Hello.

I'm currently reading about the signal transduction from G protein-coupled receptors in relation to the cAMP second messenger. But after this chapter, in every example of signal transduction, the book uses cAMP as a second messenger and activator of protein kinase A. They do this for the rest of the book. Not only in the chapter I'm currently reading.

Does this mean that cAMP is the only sencond messenger we have, or is it used only in GPCR signal transduction? Or how does it work?

Thank you.

 

[Ygggdrasil]

cAMP is one of many second messengers used in signal transduction cascades. cAMP and its regulation of PKA is probably the best/first understood second messenger cascade so it appears very frequently in textbooks. Other second messenger molecules include other cyclic nucleotides (cGMP is used as a second messenger in our photoreceptor cells), calcium ions, and lipids (e.g. diacylglycerol, phosphoinositides, and phosphatidic acids). There are almost certainly more second messengers that we have not yet discovered.

 

[uio]

Thank you very much for your help.