Abstract
The activation of heterotrimeric G-proteins is tightly regulated by the exchange of GTP for GDP in the α-subunit; mostly—but not exclusively—seven-transmembrane receptors function as the guanine nucleotide exchange factors (GEFs). A research goal may be to determine which G-protein α-subunit is activated by the receptor under investigation. In a membrane preparation obtained from cells or tissues this can be achieved in a seemingly straightforward manner by determining if the receptor increases the covalent incorporation of GTP analogs into G-protein α-subunits. Because the GTP analogs may be labeled to high specific radioactivity the α-subunit can then be identified with the use of specific antibodies (see Chapter 13). One of the compounds we present here (2′,3′-dialdehyde-GTP) can also be employed to block receptor-mediated G-protein activation and to disrupt the cognate signaling pathway.
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© 2004 Humana Press Inc.
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Hohenegger, M., Freissmuth, M., Nanoff, C. (2004). Covalent Modification of G-Proteins by Affinity Labeling. In: Willars, G.B., Challiss, R.A.J. (eds) Receptor Signal Transduction Protocols. Methods in Molecular Biology, vol 259. Humana Press. https://doi.org/10.1385/1-59259-754-8:183
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DOI: https://doi.org/10.1385/1-59259-754-8:183
Publisher Name: Humana Press
Print ISBN: 978-1-58829-329-9
Online ISBN: 978-1-59259-754-3
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