Endocytosis and Recycling of the HIV Coreceptor Ccr5

The chemokine receptor CCR5 is a cofactor for the entry of R5 tropic strains of human immunodeficiency viruses (HIV)-1 and -2 and simian immunodeficiency virus. Cells susceptible to infection by these viruses can be protected by treatment with the CCR5 ligands regulated on activation, normal T cell expressed and secreted (RANTES), MIP-1α, and MIP-1β. A major component of the mechanism through which chemokines protect cells from HIV infection is by inducing endocytosis of the chemokine receptor. Aminooxypentane (AOP)-RANTES, an NH2-terminal modified form of RANTES, is a potent inhibitor of infection by R5 HIV strains. AOP-RANTES efficiently downmodulates the cell surface expression of CCR5 and, in contrast with RANTES, appears to prevent recycling of CCR5 to the cell surface. Here, we investigate the cellular basis of this effect. Using CHO cells expressing human CCR5, we show that both RANTES and AOP-RANTES induce rapid internalization of CCR5. In the absence of ligand, CCR5 shows constitutive turnover with a half-time of 6–9 h. Addition of RANTES or AOP-RANTES has little effect on the rate of CCR5 turnover. Immunofluorescence and immunoelectron microscopy show that most of the CCR5 internalized after RANTES or AOP-RANTES treatment accumulates in small membrane-bound vesicles and tubules clustered in the perinuclear region of the cell. Colocalization with transferrin receptors in the same clusters of vesicles indicates that CCR5 accumulates in recycling endosomes. After the removal of RANTES, internalized CCR5 recycles to the cell surface and is sensitive to further rounds of RANTES-induced endocytosis. In contrast, after the removal of AOP-RANTES, most CCR5 remains intracellular. We show that these CCR5 molecules do recycle to the cell surface, with kinetics equivalent to those of receptors in RANTES-treated cells. However, these recycled CCR5 molecules are rapidly reinternalized. Our results indicate that AOP-RANTES–induced changes in CCR5 alter the steady-state distribution of the receptor and provide the first evidence for G protein–coupled receptor trafficking through the recycling endosome compartment.

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Metalloproteinase-mediated release of the ectodomain of L1 adhesion molecule

Journal of Cell Science ◽

10.1242/jcs.112.16.2667 ◽

1999 ◽

Vol 112 (16) ◽

pp. 2667-2675 ◽

Cited By ~ 1

Author(s):

S. Beer ◽

M. Oleszewski ◽

P. Gutwein ◽

C. Geiger ◽

P. Altevogt

Keyword(s):

Cell Surface ◽

Adhesion Molecule ◽

Surface Expression ◽

Cell Surface Expression ◽

Tnf Alpha ◽

Type I ◽

Ig Superfamily ◽

Cell Adhesion And Migration ◽

Membrane Bound ◽

And Migration

The L1 adhesion molecule is an approx. 200–220 kDa type I membrane glycoprotein belonging to the immunoglobulin (Ig) superfamily. L1 can bind in a homotypic fashion and was shown to support integrin-mediated binding via RGDs in the 6th Ig-like domain. In addition to its cell-surface expression, L1 can occur in the extracellular matrix (ECM). Here we demonstrate that L1 is constitutively released from the cell surface by membrane-proximal cleavage. L1 shed from B16F10 melanoma cells remains intact and can serve as substrate for integrin-mediated cell adhesion and migration. The release of L1 occurs in mouse and human cells and is blocked by the metalloproteinase inhibitor TAPI (Immunex compound 3). This compound has been shown previously to block release of L-selectin and TNF-alpha which is mediated by the membrane-bound metalloproteinase TNF-alpha converting enzyme (TACE). Using CHO cells that are low in TACE expression and do not release L-selectin we demonstrate that L1 release is distinct from L-selectin shedding. We propose that cell-surface release may be necessary for the conversion of L1 from a membrane into an ECM protein.

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The PDZ-interaction of the intestinal anion exchanger downregulated in adenoma (DRA; SLC26A3) facilitates its movement into Rab11a-positive recycling endosomes

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00132.2012 ◽

2013 ◽

Vol 304 (11) ◽

pp. G980-G990 ◽

Cited By ~ 8

Author(s):

S. Lissner ◽

C.-J. Hsieh ◽

L. Nold ◽

K. Bannert ◽

P. Bodammer ◽

...

Keyword(s):

Plasma Membrane ◽

Cell Surface ◽

Surface Expression ◽

Dominant Negative ◽

Cell Surface Expression ◽

Dominant Negative Mutant ◽

Recycling Endosomes ◽

Late Endosomes ◽

Early Endosomes ◽

Recycling Pathway

Electroneutral NaCl absorption in the ileum and colon is mediated by downregulated in adenoma (DRA) (Cl-/HCO3- exchanger; SLC26A3) and Na+/H+ exchanger 3 (NHE3, SLC9A3). Surface expression of transport proteins undergoes basal and regulated recycling by endo- and exocytosis. Expression and activity of DRA in the plasma membrane depend on intact lipid rafts, phosphatidylinositol 3-kinase (PI3-kinase), and the PDZ interaction of DRA. However, it is unknown how the PDZ interaction of DRA affects its trafficking to the cell surface. Therefore, the (re)cycling pathway of DRA was investigated in HEK cells stably expressing enhanced green fluorescent protein (EGFP)-DRA or EGFP-DRA-ETKFminus (a mutant lacking the PDZ interaction motif). Early, late, and recycling endosomes were immunoisolated by precipitating stably transfected mCherry-hemagglutinin (HA)-Rab5a, -7a, or -11a. EGFP-DRA and EGFP-DRA-ETKFminus were equally present in early endosomes. In recycling endosomes, wild-type DRA was preferentially present, whereas, in late endosomes, DRA-ETKF-minus dominated. Correspondingly, EGFP-DRA colocalized with mCherry-HA-Rab11a in recycling endosomes, whereas EGFP-DRA-ETKFminus colocalized with mCherry-HA-Rab7a in late endosomes. Functionally, this different distribution was reflected by a shorter half-life of the mutant DRA. Transient expression of dominant-negative Rab11aS25N inhibited the activity (-17%, P < 0.05) and the cell surface expression of DRA (-30%, P < 0.05). Transient transfection of Rab4a or its dominant-negative mutant Rab4aS22N was without effect and thus excluded participation of the rapid recycling pathway. Taken together, the PDZ interaction of DRA facilitates its movement into Rab11a-positive recycling endosomes, from where it is inserted in the plasma membrane. A scenario emerges where specific PDZ adaptor proteins are present along several compartments of the endocytosis-recycling pathway.

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Phorbol Esters and SDF-1 Induce Rapid Endocytosis and Down Modulation of the Chemokine Receptor CXCR4

The Journal of Cell Biology ◽

10.1083/jcb.139.3.651 ◽

1997 ◽

Vol 139 (3) ◽

pp. 651-664 ◽

Cited By ~ 279

Author(s):

Natalie Signoret ◽

Joanne Oldridge ◽

Annegret Pelchen-Matthews ◽

Per J. Klasse ◽

Thanh Tran ◽

...

Keyword(s):

Cell Surface ◽

Chemokine Receptor ◽

Phorbol Esters ◽

Surface Expression ◽

Lung Epithelial Cells ◽

Cell Surface Expression ◽

Coated Pits ◽

Terminal Domain ◽

Chemokine Receptor Cxcr4 ◽

Hiv 1

The chemokine receptor CXCR4 is required, together with CD4, for entry by some isolates of HIV-1, particularly those that emerge late in infection. The use of CXCR4 by these viruses likely has profound effects on viral host range and correlates with the evolution of immunodeficiency. Stromal cell-derived factor-1 (SDF-1), the ligand for CXCR4, can inhibit infection by CXCR4-dependent viruses. To understand the mechanism of this inhibition, we used a monoclonal antibody that is specific for CXCR4 to analyze the effects of phorbol esters and SDF-1 on surface expression of CXCR4. On human T cell lines SupT1 and BC7, CXCR4 undergoes slow constitutive internalization (1.0% of the cell surface pool/min). Addition of phorbol esters increased this endocytosis rate >6-fold and reduced cell surface CXCR4 expression by 60 to 90% over 120 min. CXCR4 was internalized through coated pits and coated vesicles and subsequently localized in endosomal compartments from where it could recycle to the cell surface after removal of the phorbol ester. SDF-1 also induced the rapid down modulation (half time ∼5 min) of CXCR4. Using mink lung epithelial cells expressing CXCR4 and a COOH-terminal deletion mutant of CXCR4, we found that an intact cytoplasmic COOH-terminal domain was required for both PMA and ligand-induced CXCR4 endocytosis. However, experiments using inhibitors of protein kinase C indicated that SDF-1 and phorbol esters trigger down modulation through different cellular mechanisms. SDF-1 inhibited HIV-1 infection of mink cells expressing CD4 and CXCR4. The inhibition of infection was less efficient for CXCR4 lacking the COOH-terminal domain, suggesting at least in part that SDF-1 inhibition of virus infection was mediated through ligand-induced internalization of CXCR4. Significantly, ligand induced internalization of CXCR4 but not CD4, suggesting that CXCR4 and CD4 do not normally physically interact on the cell surface. Together these studies indicate that endocytosis can regulate the cell-surface expression of CXCR4 and that SDF-1–mediated down regulation of cell-surface coreceptor expression contributes to chemokine-mediated inhibition of HIV infection.

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Faculty Opinions recommendation of Assembly and cell surface expression of TAP-independent, chloroquine-sensitive and interferon-gamma-inducible class I MHC complexes in transformed fibroblast cell lines are regulated by tapasin.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1009214.121258 ◽

2002 ◽

Author(s):

Tim Elliott

Keyword(s):

Cell Surface ◽

Cell Lines ◽

Interferon Gamma ◽

Fibroblast Cell ◽

Surface Expression ◽

Class I ◽

Cell Surface Expression ◽

Class I Mhc ◽

Fibroblast Cell Lines

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Faculty Opinions recommendation of Mechanism of cell surface expression of the Streptococcus mitis platelet binding proteins PblA and PblB.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1082761.535676 ◽

2007 ◽

Author(s):

Tim Mitchell

Keyword(s):

Cell Surface ◽

Binding Proteins ◽

Surface Expression ◽

Cell Surface Expression ◽

Streptococcus Mitis ◽

Platelet Binding

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Persistent HIV Transcription Induces Sialyl-Lewis-X Glyco-Antigen Cell-Surface Expression

SSRN Electronic Journal ◽

10.2139/ssrn.3565035 ◽

2020 ◽

Author(s):

Florent Colomb ◽

Leila B. Giron ◽

Leticia Kuri Cervantes ◽

Tongcui Ma ◽

Samson Adeniji ◽

...

Keyword(s):

Cell Surface ◽

Surface Expression ◽

Sialyl Lewis X ◽

Cell Surface Expression ◽

Lewis X ◽

Hiv Transcription ◽

Sialyl Lewis

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Influence of β-D-mannuronic acid, as a new member of non-steroidal anti-inflammatory drugs family, on expression pattern of chemokines and their receptors in rheumatoid arthritis

Current Drug Discovery Technologies ◽

10.2174/1570163816666191023103118 ◽

2019 ◽

Vol 16 ◽

Author(s):

Mona Aslani ◽

Arman Ahmadzadeh ◽

Zahra Aghazadeh ◽

Majid Zaki-Dizaji ◽

Laleh Sharifi ◽

...

Keyword(s):

Cell Surface ◽

Mrna Expression ◽

Surface Expression ◽

Phase Iii ◽

Cell Surface Expression ◽

Optimum Dose ◽

High Dose ◽

Mannuronic Acid ◽

Anti Inflammatory ◽

High Doses

Background: : Based on the encouraging results of phase III clinical trial of β-D-mannuronic acid (M2000) (as a new anti-inflammatory drug) in patients with RA, in this study, we aimed to evaluate the effects of this drug on the expression of chemokines and their receptors in PBMCs of RA patients. Methods:: PBMCs of RA patients and healthy controls were separated and the patients' cells were treated with low, moderate and high doses (5, 25 and 50 μg/mL) of M2000 and optimum dose (1 μg/mL) of diclofenac, as a control in RPMI-1640 medium. Real-time PCR was used for evaluating the mRNA expression of CXCR3, CXCR4, CCR2, CCR5 and CCL2/MCP-1. Cell surface expression of CCR2 was investigated using flow cytometry. Results:: CCR5 mRNA expression reduced significantly, after treatment of the patients' cells with all three doses of M2000 and optimum dose of diclofenac. CXCR3 mRNA expression down-regulated significantly followed by treatment of these cells with moderate and high doses of M2000 and optimum dose of diclofenac. CXCR4 mRNA expression declined significantly after treatment of these cells with moderate and high doses of M2000. CCL2 mRNA expression significantly reduced only followed by treatment of these cells with high dose of M2000, whereas, mRNA and cell surface expressions of CCR2 diminished significantly followed by treatment of these cells with high dose of M2000 and optimum dose of diclofenac. Conclusion:: According to our results, M2000 through the down-regulation of chemokines and their receptors may restrict the infiltration of immune cells into the synovium.

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