Optogenetic Inhibition of Gαq Protein Signaling Reduces Calcium Oscillation Stochasticity
Year: 2018
Type: article
Abstract: As fast terminators of G-protein coupled receptor (GPCR) signaling, regulators of G-protein signaling (RGS) serve critical roles in fine-tuning second messenger levels and, consequently, cellular responses to external stimuli. Here, we report the creation of an optogenetic RGS2 (opto-RGS2) that suppresses agonist-evoked calcium oscillations by the inactivation of Gα q protein. In this system, cryptochrome-mediated heterodimerization of the catalytic RGS2-box with its N-terminal amphipathic helix reconstitutes a functional membrane-localized complex that can dynamically suppress store-operated release of calcium. Engineered opto-RGS2 cell lines were used to establish the role of RGS2 as a key inhibitory feedback regulator of the stochasticity of the Gα q -mediated calcium spike timing. RGS2 reduced the stochasticity of carbachol-stimulated calcium oscillations, and the feedback inhibition was coupled to the global calcium elevation by calmodulin/RGS2 interactions. The identification of a critical negative feedback circuit exemplifies the utility of optogenetic approaches for interrogating RGS/GPCR biology and calcium encoding principles through temporally precise molecular gain-of-function.
Source: ACS Synthetic Biology
Authors: Pimkhuan Hannanta-anan, Brian Y. Chow
Institution: University of Pennsylvania
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Funders: W. W. Smith Charitable Trust, Ministry of Science and Technology of Thailand, National Institute on Drug Abuse, National Institute of Neurological Disorders and Stroke, Division of Chemical, Bioengineering, Environmental, and Transport Systems, Division of Molecular and Cellular Biosciences
OpenAlex ID: W2804649442