title: Tyrosine sulfation of the amino terminus of PSGL-1 is critical for enterovirus 71 infection.
abstract: Enterovirus 71 (EV71) is one of the major causative agents of hand, foot, and mouth disease, a common febrile disease in children; however, EV71 has been also associated with various neurological diseases including fatal cases in large EV71 outbreaks particularly in the Asia Pacific region. Recently we identified human P-selectin glycoprotein ligand-1 (PSGL-1) as a cellular receptor for entry and replication of EV71 in leukocytes. PSGL-1 is a sialomucin expressed on the surface of leukocytes, serves as a high affinity counterreceptor for selectins, and mediates leukocyte rolling on the endothelium. The PSGL-1-P-selectin interaction requires sulfation of at least one of three clustered tyrosines and an adjacent O-glycan expressing sialyl Lewis x in an N-terminal region of PSGL-1. To elucidate the molecular basis of the PSGL-1-EV71 interaction, we generated a series of PSGL-1 mutants and identified the post-translational modifications that are critical for binding of PSGL-1 to EV71. We expressed the PSGL-1 mutants in 293T cells and the transfected cells were assayed for their abilities to bind to EV71 by flow cytometry. We found that O-glycosylation on T57, which is critical for PSGL-1-selectin interaction, is not necessary for PSGL-1 binding to EV71. On the other hand, site-directed mutagenesis at one or more potential tyrosine sulfation sites in the N-terminal region of PSGL-1 significantly impaired PSGL-1 binding to EV71. Furthermore, an inhibitor of sulfation, sodium chlorate, blocked the PSGL-1-EV71 interaction and inhibited PSGL-1-mediated viral replication of EV71 in Jurkat T cells in a dose-dependent manner. Thus, the results presented in this study reveal that tyrosine sulfation, but not O-glycosylation, in the N-terminal region of PSGL-1 may facilitate virus entry and replication of EV71 in leukocytes.
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Musashimurayama-shi, Tokyo, Japan.
authors.forename: Yorihiro
authors.initials: Y
authors.lastname: Nishimura
authors.forename: Takaji
authors.initials: T
authors.lastname: Wakita
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shimizu
mesh_terms: D029821:Enterovirus A, Human / Q000472:pathogenicity*; D004769:Enterovirus Infections / Q000235:genetics / Q000378:metabolism* / Q000821:virology*; D005434:Flow Cytometry; D006031:Glycosylation; D006801:Humans; D019169:Jurkat Cells; D007962:Leukocytes / Q000821:virology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism*; D053586:Virus Internalization; D014779:Virus Replication
chemical_list: D008562:Membrane Glycoproteins; C084882:P-selectin ligand protein; D011994:Recombinant Proteins; C005662:tyrosine O-sulfate; D014443:Tyrosine