title: Nucleolin interacts with the feline calicivirus 3' untranslated region and the protease-polymerase NS6 and NS7 proteins, playing a role in virus replication.
abstract: Cellular proteins play many important roles during the life cycle of all viruses. Specifically, host cell nucleic acid-binding proteins interact with viral components of positive-stranded RNA viruses and regulate viral translation, as well as RNA replication. Here, we report that nucleolin, a ubiquitous multifunctional nucleolar shuttling phosphoprotein, interacts with the Norwalk virus and feline calicivirus (FCV) genomic 3' untranslated regions (UTRs). Nucleolin can also form a complex in vitro with recombinant Norwalk virus NS6 and -7 (NS6/7) and can be copurified with the analogous protein from feline calicivirus (p76 or NS6/7) from infected feline kidney cells. Nucleolin RNA levels or protein were not modified during FCV infection; however, as a consequence of the infection, nucleolin was seen to relocalize from the nucleoli to the nucleoplasm, as well as to the perinuclear area where it colocalizes with the feline calicivirus NS6/7 protein. In addition, antibodies to nucleolin were able to precipitate viral RNA from feline calicivirus-infected cells, indicating a direct or indirect association of nucleolin with the viral RNA during virus replication. Small interfering RNA (siRNA)-mediated knockdown of nucleolin resulted in a reduction of the cytopathic effect and virus yield in CrFK cells. Taken together, these results demonstrate that nucleolin is a nucleolar component that interacts with viral RNA and NS6/7 and is required for feline calicivirus replication.
authors.affiliation: Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, San Pedro Zacatenco, México, D.F. C.P. 07360, México.
authors.forename: Clotilde
authors.initials: C
authors.lastname: Cancio-Lonches
authors.forename: Martha
authors.initials: M
authors.lastname: Yocupicio-Monroy
authors.forename: Carlos
authors.initials: C
authors.lastname: Sandoval-Jaime
authors.forename: Iván
authors.initials: I
authors.lastname: Galvan-Mendoza
authors.forename: Luis
authors.initials: L
authors.lastname: Ureña
authors.forename: Surender
authors.initials: S
authors.lastname: Vashist
authors.forename: Ian
authors.initials: I
authors.lastname: Goodfellow
authors.forename: Juan
authors.initials: J
authors.lastname: Salas-Benito
authors.forename: Ana Lorena
authors.initials: AL
authors.lastname: Gutiérrez-Escolano
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D017927:Calicivirus, Feline / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002415:Cats; D002460:Cell Line; D007668:Kidney / Q000821:virology; D009663:Norwalk virus / Q000235:genetics / Q000378:metabolism; D010447:Peptide Hydrolases; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication; D000097796:Nucleolin
chemical_list: D020413:3' Untranslated Regions; D010447:Peptide Hydrolases; D010750:Phosphoproteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D014764:Viral Proteins; D000097796:Nucleolin