scholarly journals Chemokine receptor specific for IP10 and mig: structure, function, and expression in activated T-lymphocytes.

1996 ◽  
Vol 184 (3) ◽  
pp. 963-969 ◽  
Author(s):  
M Loetscher ◽  
B Gerber ◽  
P Loetscher ◽  
S A Jones ◽  
L Piali ◽  
...  
Keyword(s):  
Amino Acids ◽  
T Lymphocytes ◽  
Chemokine Receptors ◽  
Reading Frame ◽  
Transmembrane Segments ◽  
Activated T Lymphocytes ◽  
Cc Chemokines ◽  
Receptor Cdna ◽  
G Protein Coupled ◽  
Human Receptor

A human receptor that is selective for the CXC chemokines IP10 and Mig was cloned and characterized. The receptor cDNA has an open reading frame of 1104-bp encoding a protein of 368 amino acids with a molecular mass of 40,659 dalton. The sequence includes seven putative transmembrane segments characteristic of G-protein coupled receptors. It shares 40.9 and 40.3% identical amino acids with the two IL-8 receptors, and 34.2-36.9% identity with the five known CC chemokine receptors. The IP10/Mig receptor is highly expressed in IL-2-activated T lymphocytes, but is not detectable in resting T lymphocytes. B lymphocytes, monocytes and granulocytes. It mediates Ca2+ mobilization and chemotaxis in response to IP10 and Mig, but does not recognize the CXC-chemokines IL-8, GRO alpha, NAP-2, GCP-2. ENA78, PF4, the CC-chemokines MCP-1, MCP-2, MCP-3, MCP-4, MIP-1 alpha, MIP-1 beta. RANTES, 1309, eotaxin, nor lymphotactin. The exclusive expression in activated T-lymphocytes is of high interest since the receptors for chemokines which have been shown so far to attract lymphocytes, e.g., MCP-1, MCP-2, MCP-3, MIP-1 alpha, MIP-1 beta, and RANTES, are also found in monocytes and granulocytes. The present observations suggest that the IP10/Mig receptor is involved in the selective recruitment of effector T cells.

scholarly journals Human G Protein–Coupled Receptor Gpr-9-6/Cc Chemokine Receptor 9 Is Selectively Expressed on Intestinal Homing T Lymphocytes, Mucosal Lymphocytes, and Thymocytes and Is Required for Thymus-Expressed Chemokine–Mediated Chemotaxis

1999 ◽  
Vol 190 (9) ◽  
pp. 1241-1256 ◽  
Author(s):  
Brian A. Zabel ◽  
William W. Agace ◽  
James J. Campbell ◽  
Heidi M. Heath ◽  
David Parent ◽  
...  
Keyword(s):  
Small Intestine ◽  
T Lymphocytes ◽  
G Protein ◽  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Intraepithelial Lymphocytes ◽  
Mucosal Immune Response ◽  
G Protein Coupled Receptor ◽  
Cc Chemokine ◽  
G Protein Coupled

TECK (thymus-expressed chemokine), a recently described CC chemokine expressed in thymus and small intestine, was found to mediate chemotaxis of human G protein–coupled receptor GPR-9-6/L1.2 transfectants. This activity was blocked by anti–GPR-9-6 monoclonal antibody (mAb) 3C3. GPR-9-6 is expressed on a subset of memory α4β7high intestinal trafficking CD4 and CD8 lymphocytes. In addition, all intestinal lamina propria and intraepithelial lymphocytes express GPR-9-6. In contrast, GPR-9-6 is not displayed on cutaneous lymphocyte antigen–positive (CLA+) memory CD4 and CD8 lymphocytes, which traffic to skin inflammatory sites, or on other systemic α4β7−CLA− memory CD4/CD8 lymphocytes. The majority of thymocytes also express GPR-9-6, but natural killer cells, monocytes, eosinophils, basophils, and neutrophils are GPR-9-6 negative. Transcripts of GPR-9-6 and TECK are present in both small intestine and thymus. Importantly, the expression profile of GPR-9-6 correlates with migration to TECK of blood T lymphocytes and thymocytes. As migration of these cells is blocked by anti–GPR-9-6 mAb 3C3, we conclude that GPR-9-6 is the principal chemokine receptor for TECK. In agreement with the nomenclature rules for chemokine receptors, we propose the designation CCR-9 for GPR-9-6. The selective expression of TECK and GPR-9-6 in thymus and small intestine implies a dual role for GPR-9-6/CCR-9, both in T cell development and the mucosal immune response.

scholarly journals Comparing Native Crystal Structures and AlphaFold2 Predicted Water-Soluble G Protein-Coupled Receptor QTY Variants

Life ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1285
Author(s):  
Michael A. Skuhersky ◽  
Fei Tao ◽  
Rui Qing ◽  
Eva Smorodina ◽  
David Jin ◽  
...  
Keyword(s):  
Amino Acids ◽  
Chemokine Receptors ◽  
Protein Structures ◽  
Water Soluble ◽  
Transmembrane Helices ◽  
3 Dimensional ◽  
X Ray Crystallography ◽  
Hydrophobic Amino Acids ◽  
G Protein Coupled ◽  
Insight Into

Accurate predictions of 3-dimensional protein structures by AlphaFold2 is a game-changer for biology, especially for structural biology. Here we present the studies of several native chemokine receptors including CCR5, CCR9, CXCR2 and CXCR4 determined by X-ray crystallography, and their water-soluble QTY counter parts predicted by AlphaFold2. In the native structures, there are hydrophobic amino acids leucine (L), isoleucine (I), valine (V) and phenylalanine (F) in the transmembrane helices. These hydrophobic amino acids are systematically replaced by hydrophilic amino acids glutamine (Q), threonine (T), and tyrosine (Y). Thus, the QTY variants become water-soluble. We also present the superimposed structures of native CCR10, CXCR5, CXCR7 and an olfactory receptor OR1D2 and their water-soluble QTY variants. Since the CryoEM structural determinations for the QTY variants of CCR10QTY and OR1D2QTY are in progress, it will be of interest to compare them when the structures become available. The superimposed structures show remarkable similarity within RMSD 1Å–2Å despite significant sequence differences (~26%–~33%). We also show the differences of hydrophobicity patches between the native GPCR and their QTY variants. Our study provides insight into the subtle differences between the hydrophobic helices and hydrophilic helices, and may further stimulate designs of water-soluble membrane proteins and other aggregated proteins.

scholarly journals Interleukin-2 regulates CC chemokine receptor expression and chemotactic responsiveness in T lymphocytes.

1996 ◽  
Vol 184 (2) ◽  
pp. 569-577 ◽  
Author(s):  
P Loetscher ◽  
M Seitz ◽  
M Baggiolini ◽  
B Moser
Keyword(s):  
T Lymphocytes ◽  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Interleukin 2 ◽  
Receptor Expression ◽  
Activated T Cells ◽  
Chemokine Receptor Expression ◽  
Cc Chemokine ◽  
Cc Chemokines

Several studies have shown that CC chemokines attract T lymphocytes, and that CD45RO+, memory phenotype cells are considered to be the main responders. The results, however, have often been contradictory and the role of lymphocyte activation and proliferation has remained unclear. Using CD45RO+ blood lymphocytes cultured under different stimulatory conditions, we have now studied chemotaxis as well as chemokine receptor expression. Expression of the RANTES/MIP-1 alpha receptor (CC-CKR1) and the MCP-1 receptor (CC-CKR2) was highly correlated with migration toward RANTES, MCP-1, and other CC chemokines, and was strictly dependent on the presence of IL-2 in the culture medium. Migration and receptor expression were rapidly downregulated when IL-2 was withdrawn, but were fully restored when IL-2 was added again. The effect of IL-2 could be partially mimicked by IL-4, IL-10, or IL-12, but not by IL-13, IFN gamma, IL-1 beta, TNF-alpha, or by exposure to anti-CD3, anti-CD28 or phytohemagglutinin. Activation of fully responsive lymphocytes through the TCR/CD3 complex and CD28 antigen actually had the opposite effect. It rapidly downregulated receptor expression and consequent migration even in the presence of IL-2. In contrast to the effects on CC chemokine receptors, stimulation of CD45RO+ T lymphocytes with IL-2 neither induced the expression of the CXC chemokine receptors, IL8-R1 and IL8-R2, nor chemotaxis to IL-8. The prominent role of IL-2 in CC chemokine responsiveness of lymphocytes suggests that IL-2-mediated expansion is a prerequisite for the recruitment of antigen-activated T cells into sites of immune and inflammatory reactions.

scholarly journals The Equine Herpesvirus 2 E1 Open Reading Frame Encodes a Functional Chemokine Receptor

1999 ◽  
Vol 73 (12) ◽  
pp. 9843-9848 ◽  
Author(s):  
Grazia Camarda ◽  
Gaia Spinetti ◽  
Giovanni Bernardini ◽  
Catherine Mair ◽  
Nick Davis-Poynter ◽  
...  
Keyword(s):  
Chemokine Receptors ◽  
Amino Acid Identity ◽  
Open Reading Frames ◽  
Equine Herpesvirus ◽  
Immune Functions ◽  
Reading Frame ◽  
Cc Chemokine ◽  
Barr Virus ◽  
Epstein Barr ◽  
G Protein Coupled

ABSTRACT Several herpesviruses contain open reading frames (ORFs) that encode potential homologs of eucaryotic genes. Equine herpesvirus 2 (EHV-2) is a gammaherpesvirus related to other lymphotropic herpesviruses such as herpesvirus saimiri and Epstein-Barr virus. The E1 ORF of EHV-2, a G protein-coupled receptor homolog, shows 31 to 47% amino acid identity with known CC chemokine receptors. To investigate whether E1 may encode a functional receptor, we cloned the E1 ORF and expressed it in stably transfected cell lines. We report here the identification of the CC chemokine eotaxin as a functional ligand for the EHV-2 E1 receptor. Chemokines are likely to play a role in the regulation of immune functions in equine hosts during EHV-2 infection and, via interaction with E1, may affect viral replication and/or escape from immune responses.

Importance of the extracellular domain of the human thyrotrophin receptor for activation of cyclic AMP production

1994 ◽  
Vol 13 (2) ◽  
pp. 199-207 ◽  
Author(s):  
R Paschke ◽  
M Parmentier ◽  
G Vassart
Keyword(s):  
Amino Acids ◽  
Direct Interaction ◽  
Extracellular Domain ◽  
Receptor Activation ◽  
G Protein Coupled Receptors ◽  
Tsh Receptor ◽  
Lh Receptor ◽  
Transmembrane Segments ◽  
G Protein Coupled ◽  
Stimulation Of

ABSTRACT The mechanism by which the TSH receptor is activated is unknown. Current knowledge leads us to consider that G protein-coupled receptors are activated by positioning of their ligand in the pocket formed by the hydrophobic transmembrane segments. Furthermore, activation of an N-terminally truncated LH receptor lacking most of the extracellular domain has been described, suggesting the existence of a mechanism involving a direct interaction between LH and the transmembrane segments. The high conservation of the transmembrane segments among G protein-coupled receptors is a strong indication for a common mechanism of receptor activation. To test this hypothesis for the TSH receptor we have constructed four N-terminally truncated TSH receptor mutants with 5 or 69 amino acids of the extracellular domain joined to signal peptide regions consisting of the first 23 or 33 amino acids. The four fragments were amplified by PCR and subcloned into pBSK+. Sequences were confirmed after subcloning in M13. After joining the four fragments in pBSK+, the four TSH receptor constructs were subcloned in pSVL and transiently or stably expressed in COS and Chinese hamster ovary (CHO) cells respectively. In contrast to results obtained for the LH receptor, stimulation of the transfectants with 10 μm human chorionic gonadotrophin or 350 mU TSH/ml did not increase cyclic AMP (cAMP) concentrations in cultures of transiently transfected COS cells or stably transfected CHO cells. However, mRNA for the TSH receptor could be detected by RNase protection assay in all stable transfectants used for stimulation of cAMP. These results suggest that activation of the receptor does not implicate direct interaction of TSH with the transmembrane domains. However, our experiments could not investigate whether binding of TSH to the extracellular part of the TSH receptor can induce conformational changes of the transmembrane part, which might trigger activation of the receptor or any other role of the extracellular receptor domain as a cofactor for TSH receptor activation.

scholarly journals Human Herpesvirus 7 Open Reading Frame U12 Encodes a Functional β-Chemokine Receptor

2003 ◽  
Vol 77 (14) ◽  
pp. 8108-8115 ◽  
Author(s):  
Kazushi Nakano ◽  
Kenjiro Tadagaki ◽  
Yuji Isegawa ◽  
Mya Mya Aye ◽  
Ping Zou ◽  
...  
Keyword(s):  
Chemokine Receptors ◽  
Biological Function ◽  
Human Herpesvirus ◽  
G Protein Coupled Receptors ◽  
Biological Functions ◽  
Reading Frame ◽  
Inflammatory Protein ◽  
G Protein Coupled ◽  
Macrophage Inflammatory Protein

ABSTRACT Human herpesvirus 7 (HHV-7), which belongs to the betaherpesvirus subfamily, infects mainly CD4+ T cells in vitro and infects children during infancy. After the primary infection, HHV-7 becomes latent. HHV-7 contains two genes (U12 and U51) that encode putative homologs of cellular G-protein-coupled receptors. To analyze the biological function of the U12 gene, we cloned the gene and expressed the U12 protein in cells. The U12 gene encoded a calcium-mobilizing receptor for the EBI1 ligand chemokine-macrophage inflammatory protein 3β (ELC/MIP-3β) but not for other chemokines, suggesting that the chemokine selectivity of the U12 gene product is distinct from that of the known mammalian chemokine receptors. These studies revealed that U12 activates distinct transmembrane signaling pathways that may mediate biological functions by binding with a β-chemokine, ELC/MIP-3β.

scholarly journals Identification of CCR8: A Human Monocyte and Thymus Receptor for the CC Chemokine I-309

1997 ◽  
Vol 186 (1) ◽  
pp. 165-170 ◽  
Author(s):  
H. Lee Tiffany ◽  
Laura L. Lautens ◽  
Ji-Liang Gao ◽  
James Pease ◽  
Massimo Locati ◽  
...  
Keyword(s):  
Cell Line ◽  
Chemokine Receptors ◽  
Human Monocyte ◽  
Calcium Flux ◽  
Reading Frame ◽  
Cc Chemokine ◽  
Monogamous Relationship ◽  
Monocyte Chemotaxis ◽  
Cc Chemokines ◽  
Thymic Cell

The human CC chemokine I-309 is a potent monocyte chemoattractant and inhibits apoptosis in thymic cell lines. Here, we identify a specific human I-309 receptor, and name it CCR8 according to an accepted nomenclature system. The receptor has seven predicted transmembrane domains, is expressed constitutively in monocytes and thymus, and is encoded by a previously reported gene of previously unknown function named, alternatively, CY6, TER1, and CKR-L1. After transfection with the CY6 open reading frame, a mouse pre–B cell line exhibited calcium flux and chemotaxis in response to I-309 (EC50 = 2 nM for each), whereas 20 other chemokines were inactive. Signaling was sensitive to pertussis toxin, suggesting coupling to a Gi-type G protein. These properties parallel those of endogenous I-309 receptors expressed in an HL-60 clone 15 cell line model. The apparent monogamous relationship between I-309 and CCR8 is unusual among known CC chemokines and known CC chemokine receptors. CCR8 may regulate monocyte chemotaxis and thymic cell line apoptosis.

scholarly journals B Cell–attracting Chemokine 1, a Human CXC Chemokine Expressed in Lymphoid Tissues, Selectively Attracts B Lymphocytes via BLR1/CXCR5

1998 ◽  
Vol 187 (4) ◽  
pp. 655-660 ◽  
Author(s):  
Daniel F. Legler ◽  
Marcel Loetscher ◽  
Regula Stuber Roos ◽  
Ian Clark-Lewis ◽  
Marco Baggiolini ◽  
...  
Keyword(s):  
Amino Acids ◽  
T Lymphocytes ◽  
B Cell ◽  
B Lymphocytes ◽  
Human Blood ◽  
Dna Sequences ◽  
Chemokine Receptors ◽  
Expressed Sequence Tag ◽  
Lymphoid Tissues ◽  
Cxc Chemokine

Although most leukocytes, T lymphocytes in particular, respond to several different chemokines, there is virtually no information on chemokine activities and chemokine receptors in B lymphocytes. A putative chemokine receptor, BLR1, that is expressed in Burkitt's lymphoma cells and B lymphocytes was cloned a few years ago. Deletion of the gene for BLR1 yielded mice with abnormal primary follicles and germinal centers of the spleen and Peyer's patches, reflecting the inability of B lymphocytes to migrate into B cell areas. By screening expressed sequence tag DNA sequences, we have identified a CXC chemokine, termed B cell–attracting chemokine 1 (BCA-1), that is chemotactic for human B lymphocytes. BCA-1 cDNA encodes a protein of 109 amino acids with a leader sequence of 22 residues. The mature protein shares 23–34% identical amino acids with known CXC chemokines and is constitutively expressed in secondary lymphoid organs. BCA-1 was chemically synthesized and tested for activity on murine pre–B cells 300-19 transfected with BLR1 and on human blood B lymphocytes. In transfected cells, BCA-1 induced chemotaxis and Ca2+ mobilization demonstrating that it acts via BLR1. Under the same conditions, no activity was obtained with 10 CXC and 19 CC chemokines, lymphotactin, neurotactin/fractalkine and several other peptide ligands. BCA-1 was also a highly effective attractant for human blood B lymphocytes (which express BLR1), but was inactive on freshly isolated or IL-2–stimulated T lymphocytes, monocytes, and neutrophils. In agreement with the nomenclature rules for chemokine receptors, we propose the term CXCR5 for BLR1. Together with the observed disturbance of B cell colonization in BLR1/ CXCR5-deficient mice, the present results indicate that chemotactic recruitment by locally produced BCA-1 is important for the development of B cell areas of secondary lymphoid tissues.

scholarly journals Molecular Evaluation of the Plasma Membrane Proton Pump from Aspergillus fumigatus

2002 ◽  
Vol 46 (3) ◽  
pp. 615-624 ◽  
Author(s):  
Henriette P. Burghoorn ◽  
Patricia Soteropoulos ◽  
Padmaja Paderu ◽  
Ryota Kashiwazaki ◽  
David S. Perlin
Keyword(s):  
Amino Acids ◽  
Plasma Membrane ◽  
Aspergillus Fumigatus ◽  
Proton Pump ◽  
Sequence Motifs ◽  
Gene Encoding ◽  
Reading Frame ◽  
Conserved Sequence ◽  
Transmembrane Segments ◽  
Plasma Membrane Proton Pump

ABSTRACT The gene encoding the plasma membrane proton pump (H+-ATPase) of Aspergillus fumigatus, PMA1, was characterized from A. fumigatus strain NIH 5233 and clinical isolate H11-20. An open reading frame of 3,109 nucleotides with two introns near the N terminus predicts a protein consisting of 989 amino acids with a molecular mass of approximately 108 kDa. The predicted A. fumigatus enzyme is 89 and 51% identical to H+- ATPases of Aspergillus nidulans and Saccharomyces cerevisiae, respectively. The A. fumigatus PMA1 is a typical member of the P-type ATPase family that contains 10 predicted transmembrane segments and conserved sequence motifs TGES, CSDKTGT, MLTGD, and GDGVN within the catalytic region. The enzyme represents 2% of the total plasma membrane protein, and it is characteristically inhibited by orthovanadate, with a 50% inhibitory concentration of ∼1.8 μM. H+-ATPases from Aspergillus spp. contain a highly acidic insertion region of 60 amino acids between transmembrane segments 2 and 3, which was confirmed for the membrane-assembled enzyme with a peptide-derived antibody. An increasing A. fumigatus PMA1 copy number confers enhanced growth in low-pH medium, consistent with its role as a proton pump. These results provide support for the development of the A. fumigatus H+-ATPase as a potential drug discovery target.

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