Transduction of the Epinephrine binds to its specific receptor. NH3 GDP AC GTP OoC、Rec GTP GDP The occupied receptor Gs(asubunit)moves Adenylyl cyclase causes replacement of to adenylyl cyclase catalyzes the the gDP bound to gs and activates it formation of cAMP by gTP, activating Gs CAMP PKA is activated cyclic nucleotide phosphodiesterase by cAMP 5’AMP ( Phosphorylation of cAMP is degraded cellular proteins by reversing the PKA causes the activation of PKA cellular response to epinephrine
Transduction of the epinephrine signal: the badrenergic pathway
Se G. with GDP Contact of G G. with GTP bound is turned with hormone- bound dissoc off: it cannot receptor complex ates into a and activate adenylyl causes displace- By subunits cyclase ment of bound G。 gtp is GDP by GTP turned on: it can activate aden nylyl cyclase GTP GDP GDP GTP a G B GDP P1 GTP bound to Gsa is hydrolyzed by the proteins intrinsic GTPase; Go thereby turns itself off. The inactive a subunit reassociates with the 6, y subunits
Self-inactivation of Gs
The nobel Prize in physiology or Medicine 1994 Alfred G. Gilman Martin Rod bell 1925-1998 "for their discoveries of g-proteins and the role of these proteins in signal transduction in cells
The Nobel Prize in Physiology or Medicine 1994 “for their discoveries of G-proteins and the role of these proteins in signal transduction in cells