Biology subjects

Marti-Solano, M.

Publications and source records attributed to Marti-Solano, M..

4 recordsLinked to original sources

bioRxiv2022

Cancer-Associated Mutations Enhance The Sensitivity Of The Trupath GαQ/11 System

G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors and are a common drug target. They can be stabilised in different conformational states by ligands to activate multiple transducers and effectors leading to a variety of cellular responses. The potential of agonists to activate select pathways has important implications for drug discovery. Thus, there is a clear need to profile the initial GPCR signal transduction event, activation of G proteins, to enhance understanding of receptor coupling and guide drug design. The BRET-based biosensor suite, TRUPATH, was recently developed to enable quantification of the activation profiles of all non-visual G proteins (excluding Golf and G14) and has since been utilised in numerous studies. However, it fails to detect Gq/11 activation for a number of GPCRs previously reported to display promiscuous secondary coupling to Gq/11. Here we report modifications to the Gq and G11 biosensors in the switch I region that prevent intrinsic GTPase activity (R183C/Q). Except for the PAC1R, substitution with cancer-associated mutations, Cys or Gln, significantly increased sensitivity to allow detection of robust, reliable, and representative Gq/11 responses to Class B1 GPCRs. We also demonstrate the utility of these modified biosensors for promiscuously coupled class A GPCR that have primary Gs-coupling. Thus, we propose that modification to Gq/11 may also be necessary in other biosensor systems to enable detection of Gq/11 activation.

pharmacology and toxicology↗

bioRxiv2021

Dissecting the allosteric networks governing agonist efficacy and potency in G protein-coupled receptors

G protein-coupled receptors (GPCRs) translate binding of extracellular ligands into intracellular responses through conformational changes. Ligand properties are described by the maximum response (efficacy) and the agonist concentration at half-maximal response (potency). Integrating structural changes with pharmacological properties remains challenging and has not yet been performed at the resolution of individual amino acids. We use epinephrine and {beta}2-adrenergic receptor as a model to integrate residue-level pharmacology data with intramolecular residue contact data describing receptor activation. This unveils the allosteric networks driving ligand efficacy and potency. We provide detailed insights into how structural rearrangements are linked to fundamental pharmacological properties at single-residue level in a receptor-ligand system. Our approach can be used to determine such pharmacological networks for any receptor-ligand complex.

biochemistry↗

bioRxiv2019

GPCRmd uncovers the dynamics of the 3D-GPCRome

G protein-coupled receptors (GPCRs) are involved in numerous physiological processes and are the most frequent targets of approved drugs. The explosion in the number of new 3D molecular structures of GPCRs (3D-GPCRome) during the last decade has greatly advanced the mechanistic understanding and drug design opportunities for this protein family. While experimentally-resolved structures undoubtedly provide valuable snapshots of specific GPCR conformational states, they give only limited information on their flexibility and dynamics associated with function. Molecular dynamics (MD) simulations have become a widely established technique to explore the conformational landscape of proteins at an atomic level. However, the analysis and visualization of MD simulations requires efficient storage resources and specialized software, hence limiting the dissemination of these data to specialists in the field. Here we present the GPCRmd (http://gpcrmd.org/), an online platform that incorporates web-based visualization capabilities as well as a comprehensive and user-friendly analysis toolbox that allows scientists from different disciplines to visualize, analyse and share GPCR MD data. GPCRmd originates from a community-driven effort to create the first open, interactive, and standardized database of GPCR MD simulations. We demonstrate the power of this resource by performing comparative analyses of multiple GPCR simulations on two mechanisms critical to receptor function: internal water networks and sodium ion interaction.

biophysics↗

bioRxiv2018

Unbiased dynamic characterization of RNA-protein interactions by OOPS

Current methods for the identification of RNA-protein interactions require a quantity and quality of sample that hinders their application, especially for dynamic biological systems or when sample material is limiting. Here, we present a new approach to enrich RNA-Binding Proteins (RBPs): Orthogonal Organic Phase Separation (OOPS), which is compatible with downstream proteomics and RNA sequencing. OOPS enables recovery of RBPs and free protein, or protein-bound RNA and free RNA, from a single sample in an unbiased manner. By applying OOPS to human cell lines, we extract the majority of known RBPs, and importantly identify additional novel RBPs, including those from previously under-represented cellular compartments. The high yield and unbiased nature of OOPS facilitates its application in both dynamic and inaccessible systems. Thus, we have identified changes in RNA-protein interactions in mammalian cells following nocodazole cell-cycle arrest, and defined the first bacterial RNA-interactome. Overall, OOPS provides an easy-to-use and flexible technique that opens new opportunities to characterize RNA-protein interactions and explore their dynamic behaviour.

cell biology↗