On the Coupling of the Glucagon Receptor to Adenylate Cyclase
Two main classes of model have been proposed for the coupling of hormone receptors to adenylate cyclase across the membrane, which both assume that the catalytic unit and the receptor are distinct entities. The original model, proposed by Sutherland and coworkers,1 postulated a permanent association between the two components, in which the catalytic unit is activated by conformational changes originating in the receptor when the hormone is bound. More recently, the realisation that membrane proteins may be able to undergo fast lateral diffusion has prompted a second type of model in which the receptor and adenylate cyclase moieties can migrate independently in the plane of the membrane, until binding of the hormone to the receptor causes a locking interaction with the catalytic unit, which is then activated.2, 3, 4 The converse model, in which the catalytic unit is released from the receptor on binding hormone has also been proposed.5 At present it is not possible to distinguish these models with any confidence from the available biochemical data.
KeywordsAdenylate Cyclase Arrhenius Plot Apparent Molecular Weight Adenylate Cyclase Activity Lipid Pool
Unable to display preview. Download preview PDF.
- 6.Wisnieski, B. J., Parkes, T.G., Huang, Y.O. and Fox, C.F. (1974) Proc. Nati. Acad. Sci. U.S.A. 79, 1785–1789Google Scholar
- 7.Houslay, M.D., Metcalfe, J.C., Warren, G.B., Hesketh, T.R. and Smith, G.A. (1976) Biochim. Biophys. Acta. in press.Google Scholar
- 8.Kreiner, P.W., Keirns, J.J. and Bitensky, M.W. (1973) Proc. Nati. Acad. Sci. U.S.A. 71, 4381–4385Google Scholar
- 9.Houslay, M.D., Hesketh, T.R., Smith, G.A., Warren, G.B. and Metcalfe, J.C. (1976) Biochim. Biophys. Acta. in pressGoogle Scholar