G Proteins and Regulation of Adenylate Cyclase (Nobel Lecture)

Authors

  • Prof. Alfred G. Gilman

    Corresponding author
    1. Department of Pharmacology, The University of Texas Southwestern, Medical Center at Dallas, Dallas, TX 75235 (USA). Telefax: Int. code +(214) 648-8812
    • Department of Pharmacology, The University of Texas Southwestern, Medical Center at Dallas, Dallas, TX 75235 (USA). Telefax: Int. code +(214) 648-8812
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  • Copyright© The Nobel Foundation 1995. We thank the Nobel Foundation, Stockholm, for permission to print this lecture.

Abstract

How is the hormone-activated synthesis of the second messenger cyclic AMP regulated? Or, in more general terms, how does the interaction of an extracellular agonist with a receptor lead to intracellular enzyme activity when receptor and enzyme are not distinct macromolecules? The mediators are membrane-bound, guanine nucleotide binding regulatory proteins (G proteins). When the receptor is activated, G proteins dissociate into their subunits. These in turn activate or inhibit enzymes such as adenylate cyclases, which catalyze the synthesis of cyclic AMP. In these signal transmission processes G proteins act as molecular switches and amplifiers.

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