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SOLUTION STRUCTURE OF STROMAL CELL-DERIVED FACTOR-1 (SDF-1), NMR, MINIMIZED AVERAGE STRUCTURE
Structural highlights
FunctionSDF1_HUMAN Chemoattractant active on T-lymphocytes, monocytes, but not neutrophils. Activates the C-X-C chemokine receptor CXCR4 to induce a rapid and transient rise in the level of intracellular calcium ions and chemotaxis. Also binds to another C-X-C chemokine receptor CXCR7, which activates the beta-arrestin pathway and acts as a scavenger receptor for SDF-1. SDF-1-beta(3-72) and SDF-1-alpha(3-67) show a reduced chemotactic activity. Binding to cell surface proteoglycans seems to inhibit formation of SDF-1-alpha(3-67) and thus to preserve activity on local sites. Acts as a positive regulator of monocyte migration and a negative regulator of monocyte adhesion via the LYN kinase. Stimulates migration of monocytes and T-lymphocytes through its receptors, CXCR4 and CXCR7, and decreases monocyte adherence to surfaces coated with ICAM-1, a ligand for beta-2 integrins. SDF1A/CXCR4 signaling axis inhibits beta-2 integrin LFA-1 mediated adhesion of monocytes to ICAM-1 through LYN kinase. Inhibits CXCR4-mediated infection by T-cell line-adapted HIV-1. Plays a protective role after myocardial infarction. Induces down-regulation and internalization of CXCR7 expressed in various cells. Has several critical functions during embryonic development; required for B-cell lymphopoiesis, myelopoiesis in bone marrow and heart ventricular septum formation.[1] [2] [3] [4] [5] [6] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe three-dimensional structure of stromal cell-derived factor-1 (SDF-1) was determined by NMR spectroscopy. SDF-1 is a monomer with a disordered N-terminal region (residues 1-8), and differs from other chemokines in the packing of the hydrophobic core and surface charge distribution. Results with analogs showed that the N-terminal eight residues formed an important receptor binding site; however, only Lys-1 and Pro-2 were directly involved in receptor activation. Modification to Lys-1 and/or Pro-2 resulted in loss of activity, but generated potent SDF-1 antagonists. Residues 12-17 of the loop region, which we term the RFFESH motif, unlike the N-terminal region, were well defined in the SDF-1 structure. The RFFESH formed a receptor binding site, which we propose to be an important initial docking site of SDF-1 with its receptor. The ability of the SDF-1 analogs to block HIV-1 entry via CXCR4, which is a HIV-1 coreceptor for the virus in addition to being the receptor for SDF-1, correlated with their affinity for CXCR4. Activation of the receptor is not required for HIV-1 inhibition. Solution structure and basis for functional activity of stromal cell-derived factor-1; dissociation of CXCR4 activation from binding and inhibition of HIV-1.,Crump MP, Gong JH, Loetscher P, Rajarathnam K, Amara A, Arenzana-Seisdedos F, Virelizier JL, Baggiolini M, Sykes BD, Clark-Lewis I EMBO J. 1997 Dec 1;16(23):6996-7007. PMID:9384579[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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