Exploring the rate-limiting steps in visual phototransduction recovery by bottom-up kinetic modeling

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• dc.contributor.author Invergo, Brandon M., 1982-ca
• dc.contributor.author Montanucci, Ludovica, 1978-ca
• dc.contributor.author Koch, Karl-Wilhelmca
• dc.contributor.author Bertranpetit, Jaume, 1952-ca
• dc.contributor.author Dell'Orco, Danieleca
• dc.date.accessioned 2013-11-28T11:32:15Z
• dc.date.available 2013-11-28T11:32:15Z
• dc.date.issued 2013ca
• dc.description.abstract Phototransduction in vertebrate photoreceptor cells represents a paradigm of signaling pathways mediated by G-protein-coupled receptors (GPCRs), which share common modules linking the initiation of the cascade to the final response of the cell. In this work, we focused on the recovery phase of the visual photoresponse, which is comprised of several interacting mechanisms. We employed current biochemical knowledge to investigate the response mechanisms of a comprehensive model of the visual phototransduction pathway. In particular, we have improved the model by implementing a more detailed representation of the recoverin (Rec)-mediated calcium feedback on rhodopsin kinase and including a dynamic arrestin (Arr) oligomerization mechanism. The model was successfully employed to investigate the rate limiting steps in the recovery of the rod photoreceptor cell after illumination. Simulation of experimental conditions in which the expression levels of rhodospin kinase (RK), of the regulator of the G-protein signaling (RGS), of Arr and of Rec were altered individually or in combination revealed severe kinetic constraints to the dynamics of the overall network. Our simulations confirm that RGS-mediated effector shutdown is the rate-limiting step in the recovery of the photoreceptor and show that the dynamic formation and dissociation of Arr homodimers and homotetramers at different light intensities significantly affect the timing of rhodopsin shutdown. The transition of Arr from its oligomeric storage forms to its monomeric form serves to temper its availability in the functional state. Our results may explain the puzzling evidence that overexpressing RK does not influence the saturation time of rod cells at bright light stimuli. The approach presented here could be extended to the study of other GPCR signaling pathways.en
• dc.description.sponsorship This research was funded by grant BFU2010-19443 (subprogram BMC)/nawarded by Ministerio de Ciencia y Tecnología (Spain) and by the Direccío/nGeneral de Recerca, Generalitat de Catalunya (Grup de Recerca Consolidat/n2009SGR 1101). BMI is supported by FI-DGR and BE-DGR grants from AGAUR,/nGeneralitat de Catalunya (2011 F1 B1 00275). LM acknowledges funding from/nthe Juan de la Cierva Program of the Spanish Ministry of Science and/nInnovation (MICINN). DDO acknowledges funding from the Hanse-/nWissenschaftkolleg Delmenhorst and from the Italian Ministry for Research/nand Education (Fur2011).en
• dc.format.mimetype application/pdfca
• dc.identifier.citation Invergo BM, Montanucci L, Koch K-W, Bertranpetit J, Dell'orco D. Exploring the rate-limiting steps in visual phototransduction recovery by bottom-up kinetic modeling. Cell Commun. Signal. 2013;11(1):36. DOI: 10.1186/1478-811X-11-36ca
• dc.identifier.doi http://dx.doi.org/10.1186/1478-811X-11-36
• dc.identifier.issn 1478-811Xca
• dc.identifier.uri http://hdl.handle.net/10230/21312
• dc.language.iso engca
• dc.publisher BioMed Centralca
• dc.relation.ispartof Cell Communication and Signaling. 2013;11(1):36en
• dc.relation.projectID info:eu-repo/grantAgreement/ES/3PN/BFU2010-19443
• dc.rights © Invergo et al. Creative Commons Attribution Licenseca
• dc.rights.accessRights info:eu-repo/semantics/openAccessca
• dc.rights.uri http://creativecommons.org/licenses/by/2.0/
• dc.subject.keyword Visual phototransductionen
• dc.subject.keyword G-protein-coupled receptor signalingen
• dc.subject.keyword Arrestinen
• dc.subject.keyword Recoverinen
• dc.subject.keyword Kinetic modelingen
• dc.subject.keyword Systems biologyen
• dc.title Exploring the rate-limiting steps in visual phototransduction recovery by bottom-up kinetic modelingca
• dc.type info:eu-repo/semantics/articleca
• dc.type.version info:eu-repo/semantics/publishedVersionca