scholarly journals Mechanisms of GPCR hijacking by Staphylococcus aureus

2021 ◽  
Author(s):  
Claire M. Grison ◽  
Cédric Leyrat ◽  
Paul Lambey ◽  
Sylvain Jeannot ◽  
Elise Del Nero ◽  
...  

SUMMARYAtypical chemokine receptor 1 (ACKR1) is a G protein-coupled receptor (GPCR) targeted by Staphylococcus aureus (SA) bi-component pore-forming leukotoxins to promote bacterial growth and immune evasion. Here we have developed an integrative molecular pharmacology and structural biology approach in order to characterize the effect of leukotoxins HlgA and HlgB on ACKR1 structure and function. Interestingly, we found that both components HlgA and HlgB compete with endogenous chemokines through a direct binding to ACKR1 captured by native mass spectrometry (MS). Unexpectedly, HDX-MS analysis revealed that toxin binding allosterically modulates the intracellular G protein-binding domain of the receptor, resulting in dissociation of ACKR1–G protein complexes in living cells. Altogether, our study brings important molecular insights into the initial steps of leukotoxins targeting a host GPCR. Our findings may open the way to develop antibiotics inhibiting host receptors binding, a mechanism of action less prone to resistance.

2021 ◽  
Vol 118 (42) ◽  
pp. e2108856118
Author(s):  
Claire M. Grison ◽  
Paul Lambey ◽  
Sylvain Jeannot ◽  
Elise Del Nero ◽  
Simon Fontanel ◽  
...  

Atypical chemokine receptor 1 (ACKR1) is a G protein–coupled receptor (GPCR) targeted by Staphylococcus aureus bicomponent pore-forming leukotoxins to promote bacterial growth and immune evasion. Here, we have developed an integrative molecular pharmacology and structural biology approach in order to characterize the effect of leukotoxins HlgA and HlgB on ACKR1 structure and function. Interestingly, using cell-based assays and native mass spectrometry, we found that both components HlgA and HlgB compete with endogenous chemokines through a direct binding with the extracellular domain of ACKR1. Unexpectedly, hydrogen/deuterium exchange mass spectrometry analysis revealed that toxin binding allosterically modulates the intracellular G protein–binding domain of the receptor, resulting in dissociation and/or changes in the architecture of ACKR1−Gαi1 protein complexes observed in living cells. Altogether, our study brings important molecular insights into the initial steps of leukotoxins targeting a host GPCR.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Timothy S. Breton ◽  
William G. B. Sampson ◽  
Benjamin Clifford ◽  
Anyssa M. Phaneuf ◽  
Ilze Smidt ◽  
...  

AbstractThe SREB (Super-conserved Receptors Expressed in Brain) family of G protein-coupled receptors is highly conserved across vertebrates and consists of three members: SREB1 (orphan receptor GPR27), SREB2 (GPR85), and SREB3 (GPR173). Ligands for these receptors are largely unknown or only recently identified, and functions for all three are still beginning to be understood, including roles in glucose homeostasis, neurogenesis, and hypothalamic control of reproduction. In addition to the brain, all three are expressed in gonads, but relatively few studies have focused on this, especially in non-mammalian models or in an integrated approach across the entire receptor family. The purpose of this study was to more fully characterize sreb genes in fish, using comparative genomics and gonadal expression analyses in five diverse ray-finned (Actinopterygii) species across evolution. Several unique characteristics were identified in fish, including: (1) a novel, fourth euteleost-specific gene (sreb3b or gpr173b) that likely emerged from a copy of sreb3 in a separate event after the teleost whole genome duplication, (2) sreb3a gene loss in Order Cyprinodontiformes, and (3) expression differences between a gar species and teleosts. Overall, gonadal patterns suggested an important role for all sreb genes in teleost testicular development, while gar were characterized by greater ovarian expression that may reflect similar roles to mammals. The novel sreb3b gene was also characterized by several unique features, including divergent but highly conserved amino acid positions, and elevated brain expression in puffer (Dichotomyctere nigroviridis) that more closely matched sreb2, not sreb3a. These results demonstrate that SREBs may differ among vertebrates in genomic structure and function, and more research is needed to better understand these roles in fish.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1552
Author(s):  
Mariona Guitart-Mampel ◽  
Pedro Urquiza ◽  
Jordana I. Borges ◽  
Anastasios Lymperopoulos ◽  
Maria E. Solesio

The mineralocorticoid aldosterone regulates electrolyte and blood volume homeostasis, but it also adversely modulates the structure and function of the chronically failing heart, through its elevated production in chronic human post-myocardial infarction (MI) heart failure (HF). By activating the mineralocorticoid receptor (MR), a ligand-regulated transcription factor, aldosterone promotes inflammation and fibrosis of the heart, while increasing oxidative stress, ultimately induding mitochondrial dysfunction in the failing myocardium. To reduce morbidity and mortality in advanced stage HF, MR antagonist drugs, such as spironolactone and eplerenone, are used. In addition to the MR, aldosterone can bind and stimulate other receptors, such as the plasma membrane-residing G protein-coupled estrogen receptor (GPER), further complicating it signaling properties in the myocardium. Given the salient role that adrenergic receptor (ARs)—particularly βARs—play in cardiac physiology and pathology, unsurprisingly, that part of the impact of aldosterone on the failing heart is mediated by its effects on the signaling and function of these receptors. Aldosterone can significantly precipitate the well-documented derangement of cardiac AR signaling and impairment of AR function, critically underlying chronic human HF. One of the main consequences of HF in mammalian models at the cellular level is the presence of mitochondrial dysfunction. As such, preventing mitochondrial dysfunction could be a valid pharmacological target in this condition. This review summarizes the current experimental evidence for this aldosterone/AR crosstalk in both the healthy and failing heart, and the impact of mitochondrial dysfunction in HF. Recent findings from signaling studies focusing on MR and AR crosstalk via non-conventional signaling of molecules that normally terminate the signaling of ARs in the heart, i.e., the G protein-coupled receptor-kinases (GRKs), are also highlighted.


2016 ◽  
Vol 292 (4) ◽  
pp. 1524-1534 ◽  
Author(s):  
Stine Jørgensen ◽  
Christian Theil Have ◽  
Christina Rye Underwood ◽  
Lars Dan Johansen ◽  
Petrine Wellendorph ◽  
...  

Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2162
Author(s):  
Mohammad Taheri ◽  
Hamed Shoorei ◽  
Marcel E. Dinger ◽  
Soudeh Ghafouri-Fard

Estrogen receptors (ERs) comprise several nuclear and membrane-bound receptors with different tissue-specific functions. ERα and ERβ are two nuclear members of this family, whereas G protein-coupled estrogen receptor (GPER), ER-X, and Gq-coupled membrane estrogen receptor (Gq-mER) are membrane-bound G protein-coupled proteins. ERα participates in the development and function of several body organs such as the reproductive system, brain, heart and musculoskeletal systems. ERβ has a highly tissue-specific expression pattern, particularly in the female reproductive system, and exerts tumor-suppressive roles in some tissues. Recent studies have revealed functional links between both nuclear and membrane-bound ERs and non-coding RNAs. Several oncogenic lncRNAs and miRNAs have been shown to exert their effects through the modulation of the expression of ERs. Moreover, treatment with estradiol has been shown to alter the malignant behavior of cancer cells through functional axes composed of non-coding RNAs and ERs. The interaction between ERs and non-coding RNAs has functional relevance in several human pathologies associated with estrogen regulation, such as cancers, intervertebral disc degeneration, coronary heart disease and diabetes. In the current review, we summarize scientific literature on the role of miRNAs and lncRNAs on ER-associated signaling and related disorders.


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