Differential Modes of Regulation of CXC Chemokine-Induced Internalization and Recycling of Human Cxcr1 and Cxcr2

Feniger-Barish, Rotem; Ran, Maya; Zaslaver, Alon; Ben‐Baruch, Adit

doi:10.1006/cyto.1999.0510

Cited by 82 publications

(99 citation statements)

References 57 publications

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“…Carboxyl-terminal phosphorylation has been reported to be important for the desensitization and internalization of CXCR2 in 3ASubE cells (19), but it does not appear to be necessary for the receptor sequestration in HEK293 cells, since deletion of all the carboxyl-terminal phosphorylation sites does not affect the mutant receptor endocytosis (29). Here we show a critical role for the LLKIL motif in the carboxyl terminus of CXCR2 in the receptor internalization.…”

Section: Discussionmentioning

confidence: 52%

“…These data suggest that HEK293 cells do not express a sufficient amount of endogenous β-arrestins for regulation of CXCR1 internalization. However, FenigerBarish et al (39) observe internalization of both CXCR1 and CXCR2 in HEK293 cells in the absence of overexpression of GRK or β-arrestin. It is possible that the HEK293 cells from the two labs have different levels of β-arrestin.…”

Section: Discussionmentioning

confidence: 97%

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Identification of a Motif in the Carboxyl Terminus of CXCR2 That Is Involved in Adaptin 2 Binding and Receptor Internalization

et al. 2000

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Agonist treatment of cells expressing the chemokine receptor, CXCR2, induces receptor phosphorylation and internalization through a dynamin-dependent mechanism. In the present study, we demonstrate that a carboxyl terminus-truncated mutant of CXCR2 (331T), which no longer undergoes agonist-induced phosphorylation, continues to undergo ligand-induced internalization in HEK293 cells. This mutant receptor exhibits reduced association with β-arrestin 1 but continues to exhibit association with adaptin 2 α and β subunits. Replacing Leu320-321 and/or Ile323-Leu324 with Ala (LL320,321AA, IL323,324AA, and LLIL320,321,323,324AAAA) in wild-type CXCR2 or 331T causes little change in ligand binding and signaling through Ca 2+ mobilization but greatly impairs the agonist-induced receptor sequestration and ligand-mediated chemotaxis. The LL320,321AA, IL323,324AA, and LLIL320,321,323,324AAAA mutants of CXCR2 exhibit normal binding to β-arrestin 1 but exhibit decreased binding to adaptin 2α and β. These data demonstrate a role for the LLKIL motif in the carboxyl terminus of CXCR2 in receptor internalization and cell chemotaxis and imply a role for adaptin 2 in the endocytosis of CXCR2.The chemokine receptor, CXCR2, 1 is a member of a superfamily of G protein-coupled seventransmembrane receptors (GPCRs) that transduce intracellular signals via heterotrimeric guanine nucleotide-binding proteins (G proteins). Upon stimulation by agonists, such as interleukin 8 (IL-8) or melanoma growth-stimulatory activity (MGSA)/growth-regulatory protein (GRO), CXCR2 activates a series of G protein-mediated events, including phosphatidylinositide hydrolysis, to generate inositol 1,4,5-trisphosphate and diacylglycerol, as well as mobilization of intracellular free Ca 2+ to initiate a series of cellular responses (1). In addition, CXCR2 mediates cell chemotaxis, a distinct function of chemokine receptors (2). Like many other types of GPCRs, CXCR2 undergoes a dynamic trafficking between the cell surface and the intracellular compartments (3). Such trafficking may be involved in both transmission and termination of the receptor signals and may play an important role in mediating cell chemotaxis. For CXCR2, the most remarkable trafficking process is agonistinduced receptor internalization. 1 Abbreviations: CXCR2, receptor for CXC chemokines formerly defined as interleukin 8 receptor B; IL-8, interleukin 8; MGSA/GRO, melanoma growth-stimulatory activity/growth-regulatory protein; GPCRs, G protein-coupled receptors; G proteins, guanine nucleotidebinding proteins; β2-AR, β2-adrenergic receptor; AP-2, adaptin 2; HEK293 cells, human embryonic kidney 293 cells; RBL-2H3 cells, rabbit basophilic leukemia cells; DSP, dithiobis(succinimido propionate); GRKs, G protein-coupled receptor kinases; FITC, fluorescein isothiocyanate; BSA, bovine serum albumin; DMEM, Dulbecco's modified Eagle's medium; FBS, fetal bovine serum; PBS, phosphatebuffered saline; SDS, sodium dodecyl sulfate. Agonist-induced phosphorylation of the carboxyl terminus by G protein-couple...

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Section: Discussionmentioning

confidence: 52%

Section: Discussionmentioning

confidence: 97%

Identification of a Motif in the Carboxyl Terminus of CXCR2 That Is Involved in Adaptin 2 Binding and Receptor Internalization

et al. 2000

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“…LLLRL Motif-It has been reported that CXCL8-induced CXCR2 internalization can proceed through a carboxyl-termi- nal serine-and threonine-independent manner that is dependent on the adaptin-2-binding motif (LLKIL) in the CXCR2 carboxyl terminus (17,45). The CXCR3 carboxyl terminus contains the similar sequence LLLRL.…”

Section: Discussionmentioning

confidence: 99%

“…For example, CXCL8 (interleukin-8) activation of CXCR2 results in higher levels of receptor internalization than CXCL7 (NAP2) (17). It is not clear, however, whether CXCL8 and CXCL7 induce CXCR2 internalization through different pathways or whether the effect is because of differences in ligand potency.…”

mentioning

confidence: 99%

Intracellular Domains of CXCR3 That Mediate CXCL9, CXCL10, and CXCL11 Function

Colvin

Campanella

Sun

et al. 2004

Journal of Biological Chemistry

239

215

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The chemokine receptor CXCR3 is a G protein-coupled receptor found predominantly on T cells that is activated by three ligands as follows: CXCL9 (Mig), CXCL10 (IP-10), and CXCL11 (I-TAC). Previously, we have found that of the three ligands, CXCL11 is the most potent inducer of CXCR3 internalization and is the physiologic inducer of CXCR3 internalization after T cell contact with activated endothelial cells. We have therefore hypothesized that these three ligands transduce different signals to CXCR3. In light of this hypothesis, we sought to determine whether regions of CXCR3 are differentially required for CXCL9, CXCL10, and CXCL11 function. Here we identified two distinct domains that contributed to CXCR3 internalization. The carboxyl-terminal domain and ␤-arrestin1 were predominantly required by CXCL9 and CXCL10, and the third intracellular loop was predominantly required by CXCL11. Chemotaxis and calcium mobilization induced by all three CXCR3 ligands were dependent on the CXCR3 carboxyl terminus and the DRY sequence in the third trans-membrane domain. Our findings demonstrate that distinct domains of CXCR3 mediate its functions and suggest that the differential requirement of these domains contributes to the complexity of the chemokine system.

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“…Interaction of ␤-arrestin with clathrin and the ␤2 subunit of the AP-2 adapter complex facilitates endocytosis of agonist-bound CKRs. Following agonist removal, internalized CXCR1 and CXCR2 may be recycled to the cell surface, thereby enabling a subsequent round of signaling (13)(14)(15). The importance of CXCR1 and CXCR2 internalization to chemotactic migration is controversial.…”

mentioning

confidence: 99%

On the Mechanism and Significance of Ligand-induced Internalization of Human Neutrophil Chemokine Receptors CXCR1 and CXCR2

Rose¹,

Foley²,

Murphy

et al. 2004

Journal of Biological Chemistry

119

113

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It is well established that leukocyte chemotactic receptors, a subset of G protein-coupled receptors, undergo endocytosis after stimulation by ligand. However, the significance of this phenomenon to cell motility and other important leukocyte functions induced by chemoattractants has not been clearly defined. Here we show that in primary human neutrophils, the threshold levels of agonist required for endocytosis of the chemotactic receptors CXCR1 and CXCR2 were ϳ10-fold or higher than those needed for maximal chemotactic and calcium flux responses. Moreover, when stimulated by agonists at concentrations that are high enough for chemotaxis but too low for receptor endocytosis, neutrophil CXCR1 and CXCR2 could be reactivated in response to repeated application of the same agonist. Both receptors were excluded from Triton X-100-insoluble lipid rafts, and at high agonist concentrations were rapidly endocytosed by a clathrin/rab5/dynamin-dependent pathway. These data support the conclusion that neutrophil migration in response to CXCR1 or CXCR2 agonists is not dependent on endocytosis of CXCR1 or CXCR2. Rather than being integral to the process of cell migration, receptor endocytosis may be a terminal stop signal when cells reach the focus of inflammation where the chemoattractant concentrations are the highest.

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Differential Modes of Regulation of CXC Chemokine-Induced Internalization and Recycling of Human Cxcr1 and Cxcr2

Cited by 82 publications

References 57 publications

Identification of a Motif in the Carboxyl Terminus of CXCR2 That Is Involved in Adaptin 2 Binding and Receptor Internalization

Identification of a Motif in the Carboxyl Terminus of CXCR2 That Is Involved in Adaptin 2 Binding and Receptor Internalization

Intracellular Domains of CXCR3 That Mediate CXCL9, CXCL10, and CXCL11 Function

On the Mechanism and Significance of Ligand-induced Internalization of Human Neutrophil Chemokine Receptors CXCR1 and CXCR2

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