Constitutive Activation of CCR5 and CCR2 Induced by Conformational Changes in the Conserved TXP Motif in Transmembrane Helix 2

Arias, Diana A. Alvarez; Navenot, Jean-Marc; Zhang, Wenbo; Broach, James R.; Peiper, Stephen C.

doi:10.1074/jbc.m303739200

Cited by 39 publications

(34 citation statements)

References 50 publications

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“…Thus, CCR5-T82P can reach an active (i.e., G protein coupled) state in the absence of chemokines but undergoes agonist-mediated activation in calcium flux and chemotaxis assays. In contrast, CCR5-T82K is more strongly activated constitutively but has a dramatically impaired responsiveness to natural agonists that is associated with reduced binding affinities (26). The data from our chemokine binding assay are consistent with this earlier report: 125 I-RANTES binding to CCR5-T82K, but not CCR5-T82P, was severely compromised.…”

Section: Discussionsupporting

confidence: 90%

“…This sequence, residues 82 to 84, plays a crucial role in chemokine signaling via CCR5. Depending on the type of substitution made at residue Thr-82, the effect can range from strong impairment of CCR5 activation by chemokines to constitutive activation in their absence (26,49,50). Using ERK phosphorylation as a surrogate for CCR5 activation, our results suggest that the CCR5-T82P and CCR5-T82K variants have higher constitutive activity than that of CCR5-WT.…”

Section: Discussionmentioning

confidence: 88%

“…Using ERK phosphorylation as a surrogate for CCR5 activation, our results suggest that the CCR5-T82P and CCR5-T82K variants have higher constitutive activity than that of CCR5-WT. Earlier work has also shown that both the CCR5-T82P and CCR5-T82K CAMs bind higher basal levels of GTP␥S than that with CCR5-WT (i.e., they are constitutively coupled to G proteins), but also that their overall properties are different (26). Thus, CCR5-T82P can reach an active (i.e., G protein coupled) state in the absence of chemokines but undergoes agonist-mediated activation in calcium flux and chemotaxis assays.…”

Section: Discussionmentioning

confidence: 98%

“…Conversely, several substitutions at residue Thr-82 (e.g., T82P and T82K) in the CCR5 TM2 domain cause conformational changes that make the receptor constitutively active, in that it now signals in the absence of stimulatory ligands (26). To confirm the reported properties of the CCR5-T82P and CCR5-T82K CAMs, we measured the proportion of ERK that was phosphorylated (P-ERK) as a surrogate for CCR5 activation (41,42).…”

Section: Uncouplingmentioning

confidence: 99%

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Use of G-Protein-Coupled and -Uncoupled CCR5 Receptors by CCR5 Inhibitor-Resistant and -Sensitive Human Immunodeficiency Virus Type 1 Variants

Berro

Yasmeen

Abrol

et al. 2013

J Virol

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Small-molecule CCR5 inhibitors such as vicriviroc (VVC) and maraviroc (MVC) are allosteric modulators that impair HIV-1 entry by stabilizing a CCR5 conformation that the virus recognizes inefficiently. Viruses resistant to these compounds are able to bind the inhibitor-CCR5 complex while also interacting with the free coreceptor. CCR5 also interacts intracellularly with G proteins, as part of its signal transduction functions, and this process alters its conformation. Here we investigated whether the action of VVC against inhibitor-sensitive and -resistant viruses is affected by whether or not CCR5 is coupled to G proteins such as G␣ i . Treating CD4 ؉ T cells with pertussis toxin to uncouple the G␣ i subunit from CCR5 increased the potency of VVC against the sensitive viruses and revealed that VVC-resistant viruses use the inhibitor-bound form of G␣ i -coupled CCR5 more efficiently than they use uncoupled CCR5. Supportive evidence was obtained by expressing a signaling-deficient CCR5 mutant with an impaired ability to bind to G proteins, as well as two constitutively active mutants that activate G proteins in the absence of external stimuli. The implication of these various studies is that the association of intracellular domains of CCR5 with the signaling machinery affects the conformation of the external and transmembrane domains and how they interact with small-molecule inhibitors of HIV-1 entry.

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Section: Discussionsupporting

confidence: 90%

Section: Discussionmentioning

confidence: 88%

Section: Discussionmentioning

confidence: 98%

Section: Uncouplingmentioning

confidence: 99%

See 2 more Smart Citations

Use of G-Protein-Coupled and -Uncoupled CCR5 Receptors by CCR5 Inhibitor-Resistant and -Sensitive Human Immunodeficiency Virus Type 1 Variants

Berro

Yasmeen

Abrol

et al. 2013

J Virol

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“…TM2 is shown to strongly interact with TM3 due to a highly conserved TXP motif in TM2 among chemokine receptors whereas a TM2 -TM1 interaction is found in rhodopsin [17]. Further investigation proves a cluster of aromatic residues at the extracellular border of TM2 and TM3 are involved in chemokine-induced activation [18] and Thr in the TXP motif is involved in maintenance of the receptor in the inactive state [19].…”

Section: Hints From Mutagenesis and Computational Simulationsmentioning

confidence: 99%

An Overall Picture of Chemokine Receptors: Basic Research and Drug Development

Chen

Pei

Zhang

2004

CPD

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Abstract:Chemokine receptors belong to the transmembrane G protein coupled receptor (GPCR) family. Although a major physiological role of chemokine receptors is for host defense by recruitment of lymphocytes to inflammatory sites, they are now found to be involved in more processes such as virus infection, tumor genesis and metastasis, and embryologic development. In this review, we show an overall picture of chemokine receptors in structure, signal transduction and modulation, physiological and pathological roles, and applying chemokine receptors for drug discovery.

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Predominance of the heterozygous CCR5 delta‐24 deletion in African individuals resistant to HIV infection might be related to a defect in CCR5 addressing at the cell surface

et al. 2019

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Introduction The chemokine receptor CCR5 is the main co‐receptor for R5‐tropic HIV‐1 variants. We have previously described a novel 24‐base pair deletion in the coding region of CCR5 among individuals from Rwanda. Here, we investigated the prevalence of hCCR5Δ24 in different cohorts and its impact on CCR5 expression and HIV‐1 infection in vitro. Methods We screened hCCR5Δ24 in a total of 3232 individuals which were either HIV‐1 uninfected, high‐risk HIV‐1 seronegative and seropositive partners from serodiscordant couples, Long‐Term Survivors, or HIV‐1 infected volunteers from Africa (Rwanda, Kenya, Guinea‐Conakry) and Luxembourg, using a real‐time PCR assay. The role of the 24‐base pair deletion on CCR5 expression and HIV infection was assessed in cell lines and PBMC using mRNA quantification, confocal analysis, flow and imaging cytometry. Results and Discussion Among the 1661 patients from Rwanda, 12 individuals were heterozygous for hCCR5Δ24 but none were homozygous. Although heterozygosity for this allele may not confer complete resistance to HIV‐1 infection, the prevalence of the mutation was 2.41% (95%CI: 0.43; 8.37) in 83 Long‐Term Survivors (LTS) and 0.99% (95%CI: 0.45; 2.14) in 613 HIV‐1 exposed seronegative members as compared with 0.35% (95% Cl: 0.06; 1.25) in 579 HIV‐1 seropositive members. The prevalence of hCCR5Δ24 was 0.55% (95%CI: 0.15; 1.69) in 547 infants from Kenya but the mutation was not detected in 224 infants from Guinea‐Conakry nor in 800 Caucasian individuals from Luxembourg. Expression of hCCR5Δ24 in cell lines and PBMC showed that the hCCR5Δ24 protein is stably expressed but is not transported to the plasma membrane due to a conformational change. Instead, the mutant receptor was retained intracellularly, colocalized with an endoplasmic reticulum marker and did not mediate HIV‐1 infection. Co‐transfection of hCCR5Δ24 and wtCCR5 did not indicate a transdominant negative effect of CCR5Δ24 on wtCCR5. Conclusions Our findings indicate that hCCR5Δ24 is not expressed at the cell surface. This could explain the higher prevalence of the heterozygous hCCR5Δ24 in LTS and HIV‐1 exposed seronegative members from serodiscordant couples. Our data suggest an East‐African localization of this deletion, which needs to be confirmed in larger cohorts from African and non‐African countries.

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Constitutive Activation of CCR5 and CCR2 Induced by Conformational Changes in the Conserved TXP Motif in Transmembrane Helix 2

Abstract: CCR5 is a G protein-coupled receptor for RANTES

Cited by 39 publications

References 50 publications

Use of G-Protein-Coupled and -Uncoupled CCR5 Receptors by CCR5 Inhibitor-Resistant and -Sensitive Human Immunodeficiency Virus Type 1 Variants

Use of G-Protein-Coupled and -Uncoupled CCR5 Receptors by CCR5 Inhibitor-Resistant and -Sensitive Human Immunodeficiency Virus Type 1 Variants

An Overall Picture of Chemokine Receptors: Basic Research and Drug Development

Predominance of the heterozygous CCR5 delta‐24 deletion in African individuals resistant to HIV infection might be related to a defect in CCR5 addressing at the cell surface

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