A comprehensive model of the phototransduction cascade in mouse rod cells

Vertebrate visual phototransduction is perhaps the most well-studied G-protein signaling pathway. A wealth of available biochemical and electrophysiological data has resulted in a rich history of mathematical modeling of the system. However, while the most comprehensive models have relied upon amphibian biochemical and electrophysiological data, modern research typically employs mammalian species, particularly mice, which exhibit significantly faster signaling dynamics. In this work, we present an adaptation of a previously published, comprehensive model of amphibian phototransduction that can produce quantitatively accurate simulations of the murine photoresponse. We demonstrate the ability of the model to predict responses to a wide range of stimuli and under a variety of mutant conditions. Finally, we employ the model to highlight a likely unknown mechanism related to the interaction between rhodopsin and rhodopsin kinase.We would like to thank Alexander V. Kolesnikov for kindly providing the electrophysiological data used in the model fitting. This research was funded by grant BFU2010-19443 (subprogram BMC) awarded by the Ministerio de Ciencia y Tecnologóa (Spain) and by the Direcció General de Recerca, Generalitat de Catalunya (Grup de Recerca Consolidat 2009SGR1101). BMI was supported by FI-DGR and BE-DGR grants from AGAUR, Generalitat de Catalunya (2011 F1 B1 00275). LM acknowledges funding from the Juan de la Cierva Program of the Spanish Ministry of Science and Innovation (MICINN). DDO acknowledges funding from the Italian Ministry for Research and Education (Fur2013 Dell’Orco