title: gC1q-R/p32, a C1q-binding protein, is a receptor for the InlB invasion protein of Listeria monocytogenes.
abstract: InlB is a Listeria monocytogenes protein that promotes entry of the bacterium into mammalian cells by stimulating tyrosine phosphorylation of the adaptor proteins Gab1, Cbl and Shc, and activation of phosphatidyl- inositol (PI) 3-kinase. Using affinity chromatography and enzyme-linked immunosorbent assay, we demonstrate a direct interaction between InlB and the mammalian protein gC1q-R, the receptor of the globular part of the complement component C1q. Soluble C1q or anti-gC1q-R antibodies impair InlB-mediated entry. Transient transfection of GPC16 cells, which are non-permissive to InlB-mediated entry, with a plasmid-expressing human gC1q-R promotes entry of InlB-coated beads. Furthermore, several experiments indicate that membrane recruitment and activation of PI 3-kinase involve an InlB-gC1q-R interaction and that gC1q-R associates with Gab1 upon stimulation of Vero cells with InlB. Thus, gC1q-R constitutes a cellular receptor involved in InlB-mediated activation of PI 3-kinase and tyrosine phosphorylation of the adaptor protein Gab1. After E-cadherin, the receptor for internalin, gC1q-R is the second identified mammalian receptor promoting entry of L. monocytogenes into mammalian cells.
authors.affiliation: Unité des Interactions Bactéries-Cellules, Institut Pasteur, 28 rue du Docteur Roux, 75724 Paris cedex 15, France.
authors.forename: L
authors.initials: L
authors.lastname: Braun
authors.forename: B
authors.initials: B
authors.lastname: Ghebrehiwet
authors.forename: P
authors.initials: P
authors.lastname: Cossart
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001667:Binding, Competitive; D002352:Carrier Proteins; D002460:Cell Line; D002522:Chlorocebus aethiops; D015922:Complement C1q / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D018960:Hyaluronan Receptors; D008089:Listeria monocytogenes / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D024101:Mitochondrial Proteins; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011951:Receptors, Complement / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014443:Tyrosine / Q000378:metabolism; D014709:Vero Cells
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000906:Antibodies; D001426:Bacterial Proteins; C087299:C1QBP protein, human; D002352:Carrier Proteins; D017931:DNA Primers; C098587:GAB1 protein, human; D018960:Hyaluronan Receptors; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D010750:Phosphoproteins; D011951:Receptors, Complement; C032402:complement 1q receptor; C095768:inlB protein, Listeria monocytogenes; D014443:Tyrosine; D015922:Complement C1q