Identification of CC Chemokine Receptor 7 Residues Important for Receptor Activation

Ott, Thomas; Pahuja, Anil; Nickolls, Sarah A.; Alleva, David G.; Struthers, R. Scott

doi:10.1074/jbc.m401097200

Cited by 24 publications

(27 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although being beyond the scope of the present study, this may be suggestive of a conserved determinant for arrestin recruitment in chemokine receptors. Indeed, Lys-3.26 is highly conserved in chemokine receptors, and corresponding mutants in CXCR2 and CCR7 were found unable to signal via G proteins (43,44). It is possible, although not reported, that these mutants constitutively recruit arrestin, i.e.…”

Section: Discussionmentioning

confidence: 99%

Mutational Analysis of Atypical Chemokine Receptor 3 (ACKR3/CXCR7) Interaction with Its Chemokine Ligands CXCL11 and CXCL12

Benredjem

Girard

Rhainds

et al. 2017

Journal of Biological Chemistry

View full text Add to dashboard Cite

Edited by Henrik G. DohlmanAtypical chemokine receptors do not mediate chemotaxis or G protein signaling, but they recruit arrestin. They also efficiently scavenge their chemokine ligands, thereby contributing to gradient maintenance and termination. ACKR3, also known as CXCR7, binds and degrades the constitutive chemokine CXCL12, which also binds the canonical receptor CXCR4, and CXCL11, which also binds CXCR3. Here we report comprehensive mutational analysis of the ACKR3 interaction with its chemokine ligands, using 30 substitution mutants. Atypical chemokine receptors (ACKRs)4 are chemokine receptors that do not activate G protein-dependent signaling cascades upon agonist binding; they also do not mediate chemotaxis (1). Rather, chemokine binding to ACKRs leads to rapid chemokine internalization and degradation. Therefore, ACKRs act as chemokine scavengers and play a role in chemokine gradient reshaping, maintenance, and resolution.ACKR3, also known as CXCR7, is an atypical chemokine receptor for the constitutive chemokine CXCL12 (SDF-1), which also binds CXCR4 as a cognate canonical chemokine receptor (2). The second ACKR3 ligand is the highly regulated inflammatory chemokine CXCL11 (I-TAC), which also binds the canonical receptor CXCR3. Being unable to raise G protein responses in most cell types, agonist binding to ACKR3 nevertheless induces arrestin recruitment as a signaling response (3) and rapid degradation of both CXCL12 and CXCL11 (4). ACKR3 has been identified as a potentially promising drug target (2). Given the highly divergent role and regulation of its two ligands, selective interference with their ACKR3 interaction and scavenging may be of interest, warranting better understanding of ligand engagement and scavenging.The structures of chemokine receptors are beginning to be unraveled by crystallography, and the results are in line with those reported earlier from receptor mutagenesis-based approaches (5-7). The reported chemokine receptor crystals required co-crystallization in complex with receptor antagonists. CXCR4 was the first receptor crystallized in complex with an antagonistic chemokine ligand, the virally encoded vMIP-II, which has also permitted refined modeling of the putative CXCR4-CXCL12 complex (8). Overall, these structures refine an early two-step binding model that provides a conceptual framework for the interactions of chemokines with canonical chemokine receptors (for a recent critical review of this model see Kleist et al.; Ref. 9). Following this model, initial chemokine interaction with the receptor critically depends on the receptor N terminus, and some extracellular loop residues. This is then followed by secondary interaction mainly involving the chemokine N terminus with receptor binding pocket residues; this second interaction is required for receptor activation. Of note, for CXCR4 the two-step interaction model is supported by 4 The abbreviations used are: ACKR, atypical chemokine receptor; BRET, bioluminescence resonance energy transfer; CRS1, chemokine recognition...

show abstract

Section: Discussionmentioning

confidence: 99%

Mutational Analysis of Atypical Chemokine Receptor 3 (ACKR3/CXCR7) Interaction with Its Chemokine Ligands CXCL11 and CXCL12

Benredjem

Girard

Rhainds

et al. 2017

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…This motif could account for the differential signaling described here by a variety of mechanisms, including tethering CCL21 to extracellular glycosaminoglycans or by differentially inducing ligand oligomerization. Alternatively, because the amino acids of the N terminus of CCL19 have been shown to regulate receptor activation (36)(37)(38), subtle differences in the primary structure in this region may account for differential signaling. Thus, additional studies using chimeric ligands could test the relative importance of these motifs for CCR7 ligand bias.…”

Section: Discussionmentioning

confidence: 99%

Selective engagement of G protein coupled receptor kinases (GRKs) encodes distinct functions of biased ligands

Zidar¹,

Violin²,

Whalen³

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

244

261

View full text Add to dashboard Cite

CCL19 and CCL21 are endogenous agonists for the seven-transmembrane receptor CCR7. They are equally active in promoting G protein stimulation and chemotaxis. Yet, we find that they result in striking differences in activation of the G protein-coupled receptor kinase (GRK)/ß-arrestin system. CCL19 leads to robust CCR7 phosphorylation and ␤-arrestin2 recruitment catalyzed by both GRK3 and GRK6 whereas CCL21 activates GRK6 alone. This differential GRK activation leads to distinct functional consequences. Although each ligand leads to ␤-arrestin2 recruitment, only CCL19 leads to redistribution of ␤-arrestin2-GFP into endocytic vesicles and classical receptor desensitization. In contrast, these agonists are both capable of signaling through GRK6 and ␤-arrestin2 to ERK kinases. Thus, this mechanism for ''ligand bias'' whereby endogenous agonists activate different GRK isoforms leads to functionally distinct pools of ␤-arrestin.

show abstract

“…The easy-totransfect Jurkat TAg cells express the large T antigen of simian virus 40 (SV40) and were grown in RPMI 1640 medium supplemented with 10% fetal calf serum (FCS), 100 U/ml penicillin, and 100 g/ml streptomycin (all from Gibco). Jurkat-CCR7 cells were a gift from Scott R. Struthers (University of California, San Diego, CA) (29) and were maintained in Dulbecco's modified Eagle (DME) medium supplemented with 10% FCS, 100 U/ml penicillin, 100 g/ml streptomycin, 1ϫ nonessential amino acids, 1ϫ sodium pyruvate (all from Gibco), and 0.65 M ␤-mercaptoethanol (Sigma). Compared to Jurkat TAg cells, Jurkat-CCR7 cells exhibit low background actin remodeling and chemotaxis activity in the absence of chemokine and thus increased responsiveness to chemokine treatment.…”

Section: Methodsmentioning

confidence: 99%

Lentiviral Nef Proteins Utilize PAK2-Mediated Deregulation of Cofilin as a General Strategy To Interfere with Actin Remodeling

Stolp

Abraham

Rudolph

et al. 2010

J Virol

View full text Add to dashboard Cite

Nef is an accessory protein and pathogenicity factor of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) which elevates virus replication in vivo. We recently described for HIV type 1 SF2 (HIV-1 SF2 ) the potent interference of Nef with T-lymphocyte chemotaxis via its association with the cellular kinase PAK2. Mechanistic analysis revealed that this interaction results in deregulation of the actin-severing factor cofilin and thus blocks the chemokine-mediated actin remodeling required for cell motility. However, the efficiency of PAK2 association is highly variable among Nef proteins from different lentiviruses, prompting us to evaluate the conservation of this actin-remodeling/cofilin-deregulating mechanism. Based on the analysis of a total of 17 HIV-1, HIV-2, and SIV Nef proteins, we report here that inhibition of chemokine-induced actin remodeling as well as inactivation of cofilin are strongly conserved activities of lentiviral Nef proteins. Of note, even for Nef variants that display only marginal PAK2 association in vitro, these activities require the integrity of a PAK2 recruitment motif and the presence of endogenous PAK2. Thus, reduced in vitro affinity to PAK2 does not indicate limited functionality of Nef-PAK2 complexes in intact HIV-1 host cells. These results establish hijacking of PAK2 for deregulation of cofilin and inhibition of triggered actin remodeling as a highly conserved function of lentiviral Nef proteins, supporting the notion that PAK2 association may be critical for Nef's activity in vivo.

show abstract

Identification of CC Chemokine Receptor 7 Residues Important for Receptor Activation

Cited by 24 publications

References 52 publications

Mutational Analysis of Atypical Chemokine Receptor 3 (ACKR3/CXCR7) Interaction with Its Chemokine Ligands CXCL11 and CXCL12

Mutational Analysis of Atypical Chemokine Receptor 3 (ACKR3/CXCR7) Interaction with Its Chemokine Ligands CXCL11 and CXCL12

Selective engagement of G protein coupled receptor kinases (GRKs) encodes distinct functions of biased ligands

Lentiviral Nef Proteins Utilize PAK2-Mediated Deregulation of Cofilin as a General Strategy To Interfere with Actin Remodeling

Contact Info

Product

Resources

About