Cellular Secondary Messengers: Calcium, IP3 and cAMP

Solution Preview

Second messengers like calcium and inositol-3-phosphate (IP3) are closely related in function. Cyclic adenosine monophosphate (cAMP) can be associated to the other two as a second messenger that acts through GTP coupled receptors. A typical hormone receptor, for example, has three subunits referred to as α, β, and γ. Binding of the ligand results in a dissociation of the α-subunit bound with GTP. GDP was previously bound but is displaced with GTP once the ligand is bound. Subsequent pathways can separate at this point in regard to the downstream events of cAMP and Ca/IP3 dependent on the cell or receptor type. cAMP will be produced ...