3uez | pdb_00003uez
Crystal structure of the human Colony-Stimulating Factor 1 (hCSF-1) cytokine in complex with the viral receptor BARF1
Structural highlights
FunctionBARF1_EBVB9 Plays diverse functions in immunomodulation and oncogenicity, maybe by acting as a functional receptor for human CSF1. May inhibit interferon secretion from mononuclear cells. Exhibits oncogenic activity in vitro.[1] [2] [3] Publication Abstract from PubMedHematopoietic human colony-stimulating factor 1 (hCSF-1) is essential for innate and adaptive immunity against viral and microbial infections and cancer. The human pathogen Epstein-Barr virus secretes the lytic-cycle protein BARF1 that neutralizes hCSF-1 to achieve immunomodulation. Here we show that BARF1 binds the dimer interface of hCSF-1 with picomolar affinity, away from the cognate receptor-binding site, to establish a long-lived complex featuring three hCSF-1 at the periphery of the BARF1 toroid. BARF1 locks dimeric hCSF-1 into an inactive conformation, rendering it unable to signal via its cognate receptor on human monocytes. This reveals a new functional role for hCSF-1 cooperativity in signaling. We propose a new viral strategy paradigm featuring an allosteric decoy receptor of the competitive type, which couples efficient sequestration and inactivation of the host growth factor to abrogate cooperative assembly of the cognate signaling complex. Allosteric competitive inactivation of hematopoietic CSF-1 signaling by the viral decoy receptor BARF1.,Elegheert J, Bracke N, Pouliot P, Gutsche I, Shkumatov AV, Tarbouriech N, Verstraete K, Bekaert A, Burmeister WP, Svergun DI, Lambrecht BN, Vergauwen B, Savvides SN Nat Struct Mol Biol. 2012 Sep;19(9):938-47. doi: 10.1038/nsmb.2367. Epub 2012 Aug, 19. PMID:22902366[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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