Epinephrine Signalling Pathway,
The Signalling molecule for this pathway is Epinephrine that is received by the Beta Adrenergic Receptor. The Beta Adrenergic receptor is from the GPCR family.
In this video we have discussed about the Epinephrine Signalling Pathway , that encompasses the cAMP as a second messenger .
Adrenaline causes liver cells to release glucose into the blood, acting through both alpha and beta adrenergic receptors to stimulate glycogenolysis. Adrenaline binds to β2 receptors on liver cells, which changes conformation and helps Gs, a heterotrimeric G protein, exchange GDP to GTP. This trimeric G protein dissociates to Gs alpha and Gs beta/gamma subunits. Gs alpha stimulates adenylyl cyclase, thus converting adenosine triphosphate into cyclic adenosine monophosphate (AMP). Cyclic AMP activates protein kinase A. Protein kinase A phosphorylates and partially activates phosphorylase kinase. Adrenaline also binds to α1 adrenergic receptors, causing an increase in inositol trisphosphate, inducing calcium ions to enter the cytoplasm. Calcium ions bind to calmodulin, which leads to further activation of phosphorylase kinase. Phosphorylase kinase phosphorylates glycogen phosphorylase, which then breaks down glycogen leading to the production of glucose.