title: Binding of cellular p32 protein to the rubella virus P150 replicase protein via PxxPxR motifs.
abstract: A proline-rich region (PRR) within the rubella virus (RUBV) P150 replicase protein that contains three SH3 domain-binding motifs (PxxPxR) was investigated for its ability to bind cell proteins. Pull-down experiments using a glutathione S-transferase-PRR fusion revealed PxxPxR motif-specific binding with human p32 protein (gC1qR), which could be mediated by either of the first two motifs. This finding was of interest because p32 protein also binds to the RUBV capsid protein. Binding of p32 to P150 was confirmed and was abolished by mutation of the first two motifs. When mutations in the first two motifs were introduced into a RUBV cDNA infectious clone, virus replication was significantly impaired. However, virus RNA synthesis was found to be unaffected, and subsequent immunofluorescence analysis of RUBV-infected cells revealed co-localization of p32 and P150 but little overlap of p32 with RNA replication complexes, indicating that p32 does not participate directly in virus RNA synthesis. Thus, the role of p32 in RUBV replication remains unresolved.
authors.affiliation: Department of Biology, Georgia State University, Atlanta, GA 30303, USA.
authors.forename: Suganthi
authors.initials: S
authors.lastname: Suppiah
authors.affiliation: Department of Biology, Georgia State University, Atlanta, GA 30303, USA.
authors.forename: Heather A
authors.initials: HA
authors.lastname: Mousa
authors.affiliation: Department of Biology, Georgia State University, Atlanta, GA 30303, USA.
authors.forename: Wen-Pin
authors.initials: WP
authors.lastname: Tzeng
authors.affiliation: Department of Biology, Georgia State University, Atlanta, GA 30303, USA.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Matthews
authors.affiliation: Department of Biology, Georgia State University, Atlanta, GA 30303, USA.
authors.forename: Teryl K
authors.initials: TK
authors.lastname: Frey
mesh_terms: D000818:Animals; D036022:Capsid Proteins / Q000378:metabolism / Q000502:physiology; D002352:Carrier Proteins / Q000378:metabolism*; D002522:Chlorocebus aethiops; D006801:Humans; D024101:Mitochondrial Proteins / Q000378:metabolism*; D055232:Proline-Rich Protein Domains / Q000235:genetics / Q000502:physiology*; D011485:Protein Binding; D012367:RNA, Viral / Q000378:metabolism / Q000502:physiology; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D012412:Rubella virus / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014709:Vero Cells; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D014779:Virus Replication / Q000235:genetics / Q000502:physiology; D018909:src Homology Domains / Q000502:physiology
chemical_list: C087299:C1QBP protein, human; D036022:Capsid Proteins; D002352:Carrier Proteins; D024101:Mitochondrial Proteins; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins; D012324:RNA-Dependent RNA Polymerase