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Updated: Oct 13, 2026

Strategic Screening and Characterization of the Visual GPCR-mini-G Protein Signaling Complex for Successful Crystallization
Published on: March 16, 2020
Enhanced GTPase activity of transducin when bound to cGMP phosphodiesterase in bovine retinal rods
F Pagès1, P Deterre, C Pfister
1Département de Biologie Moléculaire et Structurale, Centre d'Etudes Nucléaires de Grenoble, France.
Abstract:
The generation of the physiological response of a retinal rod cell to an incident photon involves activation of a cGMP phosphodiesterase (PDE) by a GTP-binding protein, transducin (T). This activation has been shown to occur by formation of a membrane-bound T alpha GTP-PDE complex (Clerc, A., and Bennett, N. (1992) J. Biol. Chem. 267, 6620-6627; Catty, P., Pfister, C., Bruckert, F., and Deterre, P. (1992) J. Biol. Chem 267, 19489-19493). The recovery of the response involves turning-off of T by its intrinsic GTPase activity. We show here that the formation of the membrane-bound T alpha GTP-PDE complex correlates with an enhanced rate of GTP hydrolysis. In vivo, this would provide an appropriate mechanism for fast turn-off of cGMP hydrolysis.
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