Marcus Thelen

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Combined phylogenetic and chromosomal location studies suggest that the orphan receptor RDC1 is related to CXC chemokine receptors. RDC1 provides a co-receptor function for a restricted number of human immunodeficiency virus (HIV) isolates, in particular for the CXCR4-using HIV-2 ROD strain. Here we show that CXCL12, the only known natural ligand for CXCR4,(More)
The dynamic properties of the cell cortex and its actin cytoskeleton determine important aspects of cell behavior and are a major target of cell regulation. GAP43, myristoylated alanine-rich C kinase substrate (MARCKS), and CAP23 (GMC) are locally abundant, plasmalemma-associated PKC substrates that affect actin cytoskeleton. Their expression correlates(More)
BACKGROUND CXCR7 (RDC1), the recently discovered second receptor for CXCL12, is phylogenetically closely related to chemokine receptors, but fails to couple to G-proteins and to induce typical chemokine receptor mediated cellular responses. The function of CXCR7 is controversial. Some studies suggest a signaling activity in mammalian cells and zebrafish(More)
CXCR7, formerly called RDC1 is a recently deorphanized G-protein coupled receptor which binds with high affinity the inflammatory and homing chemokines CXCL11/ITAC and CXCL12/SDF-1. Despite its phylogenetic relation and ligand binding properties CXCR7 does not mediate typical chemokine receptor responses such as leukocyte trafficking. Recent findings in(More)
Biological properties of chemokines are believed to be influenced by their association with glycosaminoglycans. Surface plasmon resonance kinetic analysis shows that the CXC chemokine stromal cell-derived factor-1alpha (SDF-1alpha), which binds the CXCR4 receptor, associates with heparin with an affinity constant of 38.4 nM (k(on) = 2.16 x 10(6) M(-1) s(-1)(More)
After tissue damage, inflammatory cells infiltrate the tissue and release proinflammatory cytokines. HMGB1 (high mobility group box 1), a nuclear protein released by necrotic and severely stressed cells, promotes cytokine release via its interaction with the TLR4 (Toll-like receptor 4) receptor and cell migration via an unknown mechanism. We show that(More)
Sixteen years ago, the Nomenclature Committee of the International Union of Pharmacology approved a system for naming human seven-transmembrane (7TM) G protein-coupled chemokine receptors, the large family of leukocyte chemoattractant receptors that regulates immune system development and function, in large part by mediating leukocyte trafficking. This was(More)
Wortmannin (WT) and its derivative 17-hydroxywortmannin (HWT) inhibit at nanomolar concentrations superoxide formation and exocytosis in neutrophils stimulated with chemotactic agonists. Treatment of neutrophils with radiolabeled [3H]HWT resulted in specific and saturable binding that paralleled the inhibition of the respiratory burst. Both half-maximal(More)
Since their discovery 13 years ago, chemokines have emerged as the most important regulators of leukocyte trafficking. On target cells, chemokines bind to seven-transmembrane-domain receptors that are coupled to heterotrimeric Gi proteins. The common response of all cells to chemokine stimulation is chemotaxis. In addition, leukocyte activation triggers(More)
The chemokine CXCL12 promotes migration of human leukocytes, hematopoietic progenitors, and tumor cells. The binding of CXCL12 to its receptor CXCR4 triggers Gi protein signals for motility and integrin activation in many cell types. CXCR7 is a second, recently identified receptor for CXCL12, but its role as an intrinsic G-protein-coupled receptor (GPCR)(More)