In: Biology
Diagram an adrenergic receptor. Label the ligand-binding domain. Label the transmembrane domain. Label the intracellular domain. Name a ligand for an adrenergic receptor. What happens to the adrenergic receptor when this ligand binds?
Here is the required diagram.
A ligand for adrenergic receptor is Epinephrine.
When Epinephrine binds to this beta- Adrenergic receptor, causes a conformational change in the receptor thereby activating its intracellular domain which activate a protein called G-protein. This G-protein has two states- activated and inactivated. Inactivated state has GDP bound to it but after binding to epinephrine, this GDP is replaced by GTP and thus the GTP protein becomes active.GTP has three subunits- alpha,beta,gamma.The freed alpha subunit then goes and interact with adenylate cyclase which catalyzes the formation of cAMP (a second messenger). This cAMP propagates messenge to many signalling pathway which it accomplishes by actvating protein kinase A which in turn catalyzes the phosphorylation of many different proteins. For example - Glycogen synthesis enzymes ate turned of by phosphorylation whereas glycogen breakdown enzymes are turned on by phosphorylation, etc.