title: Characterization of a nuclear localization signal in the foot-and-mouth disease virus polymerase.
abstract: We have experimentally tested whether the MRKTKLAPT sequence in FMDV 3D protein (residues 16 to 24) can act as a nuclear localization signal (NLS). Mutants with substitutions in two basic residues within this sequence, K18E and K20E, were generated. A decreased nuclear localization was observed in transiently expressed 3D and its precursor 3CD, suggesting a role of K18 and K20 in nuclear targeting. Fusion of MRKTKLAPT to the green fluorescence protein (GFP) increased the nuclear localization of GFP, which was not observed when GFP was fused to the 3D mutated sequences. These results indicate that the sequence MRKTKLAPT can be functionally considered as a NLS. When introduced in a FMDV full length RNA replacements K18E and K20E led to production of revertant viruses that replaced the acidic residues introduced (E) by K, suggesting that the presence of lysins at positions 18 and 20 of 3D is essential for virus multiplication.
authors.affiliation: Centro de Biología Molecular, "Severo Ochoa" (CSIC-UAM), Cantoblanco 28049, Madrid, Spain.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Sanchez-Aparicio
authors.forename: Maria Flora
authors.initials: MF
authors.lastname: Rosas
authors.forename: Francisco
authors.initials: F
authors.lastname: Sobrino
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D000956:Antigens, Viral / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D002467:Cell Nucleus / Q000737:chemistry; D006224:Cricetinae; D004252:DNA Mutational Analysis; D029544:Foot-and-Mouth Disease Virus / Q000235:genetics*; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D019913:Nuclear Localization Signals; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000235:genetics; D017361:Viral Nonstructural Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D000956:Antigens, Viral; D019913:Nuclear Localization Signals; D011993:Recombinant Fusion Proteins; D017361:Viral Nonstructural Proteins; C103557:virus-infection-associated antigen, Foot-and-mouth disease virus; D049452:Green Fluorescent Proteins
keywords: FMDV; NLS; Viral polymerase