title: Human protein Sam68 relocalization and interaction with poliovirus RNA polymerase in infected cells.
abstract: A HeLa cDNA expression library was screened for human polypeptides that interacted with the poliovirus RNA-dependent RNA polymerase, 3D, using the two-hybrid system in the yeast Saccharomyces cerevisiae. Sam68 (Src-associated in mitosis, 68 kDa) emerged as the human cDNA that, when fused to a transcriptional activation domain, gave the strongest 3D interaction signal with a LexA-3D hybrid protein. 3D polymerase and Sam68 coimmunoprecipitated from infected human cell lysates with antibodies that recognized either protein. Upon poliovirus infection, Sam68 relocalized from the nucleus to the cytoplasm, where poliovirus replication occurs. Sam68 was isolated from infected cell lysates with an antibody that recognizes poliovirus protein 2C, suggesting that it is found on poliovirus-induced membranes upon which viral RNA synthesis occurs. These data, in combination with the known RNA- and protein-binding properties of Sam68, make Sam68 a strong candidate for a host protein with a functional role in poliovirus replication.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology and Howard Hughes Medical Institute, University of Colorado, Boulder 80309-0347, USA.
authors.forename: A E
authors.initials: AE
authors.lastname: McBride
authors.forename: A
authors.initials: A
authors.lastname: Schlegel
authors.forename: K
authors.initials: K
authors.lastname: Kirkegaard
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D002451:Cell Compartmentation; D002462:Cell Membrane / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D010750:Phosphoproteins / Q000378:metabolism*; D011051:Poliomyelitis / Q000378:metabolism; D017955:Poliovirus / Q000201:enzymology*; D011233:Precipitin Tests; D011485:Protein Binding; D016601:RNA-Binding Proteins / Q000378:metabolism*; D014764:Viral Proteins / Q000378:metabolism; D014779:Virus Replication
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D004268:DNA-Binding Proteins; C074561:GAP-associated protein p62; C489559:KHDRBS1 protein, human; D010750:Phosphoproteins; D016601:RNA-Binding Proteins; D014764:Viral Proteins; D012321:DNA-Directed RNA Polymerases