scholarly journals Delineation of molecular determinants for FR900359 inhibition of Gq/11 unlocks inhibition of Gαs

2020 ◽  
Vol 295 (40) ◽  
pp. 13850-13861
Author(s):  
Michael W. Boesgaard ◽  
Kasper Harpsøe ◽  
Michelle Malmberg ◽  
Christina R. Underwood ◽  
Asuka Inoue ◽  
...  

Heterotrimeric G proteins are essential mediators of intracellular signaling of G protein–coupled receptors. The Gq/11 subfamily consists of Gq, G11, G14, and G16 proteins, of which all but G16 are inhibited by the structurally related natural products YM-254890 and FR900359. These inhibitors act by preventing the GDP/GTP exchange, which is necessary for activation of all G proteins. A homologous putative binding site for YM-254890/FR900359 can also be found in members of the other three G protein families, Gs, Gi/o, and G12/13, but none of the published analogs of YM-254890/FR900359 have shown any inhibitory activity for any of these. To explain why the YM-254890/FR900359 scaffold only inhibits Gq/11/14, the present study delineated the molecular selectivity determinants by exchanging amino acid residues in the YM-254890/FR900359–binding site in Gq and Gs. We found that the activity of a Gs mutant with a Gq-like binding site for YM-254890/FR900359 can be inhibited by FR900359, and a minimum of three mutations are necessary to introduce inhibition in Gs. In all, this suggests that although the YM-254890/FR900359 scaffold has proven unsuccessful to derive Gs, Gi/o, and G12/13 inhibitors, the mechanism of inhibition between families of G proteins is conserved, opening up the possibility of targeting by other, novel inhibitor scaffolds. In lack of a selective Gαs inhibitor, FR900359-sensitive Gαs mutants may prove useful in studies where delicate control over Gαs signaling would be of the essence.

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 222
Author(s):  
Agnieszka Polit ◽  
Paweł Mystek ◽  
Ewa Błasiak

In highly organized multicellular organisms such as humans, the functions of an individual cell are dependent on signal transduction through G protein-coupled receptors (GPCRs) and subsequently heterotrimeric G proteins. As most of the elements belonging to the signal transduction system are bound to lipid membranes, researchers are showing increasing interest in studying the accompanying protein–lipid interactions, which have been demonstrated to not only provide the environment but also regulate proper and efficient signal transduction. The mode of interaction between the cell membrane and G proteins is well known. Despite this, the recognition mechanisms at the molecular level and how the individual G protein-membrane attachment signals are interrelated in the process of the complex control of membrane targeting of G proteins remain unelucidated. This review focuses on the mechanisms by which mammalian Gα subunits of G proteins interact with lipids and the factors responsible for the specificity of membrane association. We summarize recent data on how these signaling proteins are precisely targeted to a specific site in the membrane region by introducing well-defined modifications as well as through the presence of polybasic regions within these proteins and interactions with other components of the heterocomplex.


2000 ◽  
Vol 275 (28) ◽  
pp. 21730-21736 ◽  
Author(s):  
Shigetomo Fukuhara ◽  
Maria Julia Marinissen ◽  
Mario Chiariello ◽  
J. Silvio Gutkind

2009 ◽  
Vol 23 (5) ◽  
pp. 590-599 ◽  
Author(s):  
Jean-Pierre Vilardaga ◽  
Moritz Bünemann ◽  
Timothy N. Feinstein ◽  
Nevin Lambert ◽  
Viacheslav O. Nikolaev ◽  
...  

Abstract Many biochemical pathways are driven by G protein-coupled receptors, cell surface proteins that convert the binding of extracellular chemical, sensory, and mechanical stimuli into cellular signals. Their interaction with various ligands triggers receptor activation that typically couples to and activates heterotrimeric G proteins, which in turn control the propagation of secondary messenger molecules (e.g. cAMP) involved in critically important physiological processes (e.g. heart beat). Successful transfer of information from ligand binding events to intracellular signaling cascades involves a dynamic interplay between ligands, receptors, and G proteins. The development of Förster resonance energy transfer and bioluminescence resonance energy transfer-based methods has now permitted the kinetic analysis of initial steps involved in G protein-coupled receptor-mediated signaling in live cells and in systems as diverse as neurotransmitter and hormone signaling. The direct measurement of ligand efficacy at the level of the receptor by Förster resonance energy transfer is also now possible and allows intrinsic efficacies of clinical drugs to be linked with the effect of receptor polymorphisms.


2016 ◽  
Vol 9 (423) ◽  
pp. pc9-pc9
Author(s):  
Mikel Garcia-Marcos ◽  
Annalisa M. VanHook

AbstractThis Podcast features an interview with Mikel Garcia-Marcos, author of a Research Article that appears in the 12 April 2016 issue of Science Signaling, about how mutations in a G protein cause auriculo-condylar syndrome (ACS). ACS is caused by mutations that affect signaling through the endothelin type A receptor (ETAR) and is characterized by craniofacial abnormalities resulting from defects in neural crest development. ETAR is a G protein–coupled receptor (GPCR) that signals primarily through heterotrimeric G proteins containing Gαq/11, but mutations in Gαi3 are also associated with ACS. Marivin et al. found that ETAR coupled to ACS-associated mutant forms of Gαi3 instead of coupling to Gαq/11. These mutant forms of Gαi3 lacked enzymatic activity and thus blocked ETAR signaling.Listen to Podcast


1998 ◽  
Vol 274 (5) ◽  
pp. G792-G796
Author(s):  
Karen McConalogue ◽  
Nigel W. Bunnett

Neuropeptides exert their diverse biological effects by interacting with G protein-coupled receptors (GPCRs). In this review we address the question, What regulates the ability of a target cell, in particular a neuron, to respond to a neuropeptide? Available evidence from studies of many GPCRs in reconstituted systems and transfected cell lines indicates that much of this regulation occurs at the level of the receptor and serves to alter the capacity of the receptor to bind ligands with high affinity and to couple to heterotrimeric G proteins. Although some of the knowledge gained from these studies is applicable to the regulation of neuropeptide receptors on neurons, at present there are far more questions than answers.


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