title: Lolium latent virus (Alphaflexiviridae) coat proteins: expression and functions in infected plant tissue.
abstract: The genome of Lolium latent virus (LoLV; genus Lolavirus, family Alphaflexiviridae) is encapsidated by two carboxy-coterminal coat protein (CP) variants (about 28 and 33 kDa), in equimolar proportions. The CP ORF contains two 5'-proximal AUGs encoding Met 1 and Met 49, respectively promoting translation of the 33 and 28 kDa CP variants. The 33 kDa CP N-terminal domain includes a 42 aa sequence encoding a putative chloroplast transit peptide, leading to protein cleavage and alternative derivation of the approximately 28 kDa CP. Mutational analysis of the two in-frame start codons and of the putative proteolytic-cleavage site showed that the N-terminal sequence is crucial for efficient cell-to-cell movement, functional systemic movement, homologous CP interactions and particle formation, but is not required for virus replication. Blocking production of the 28 kDa CP by internal initiation shows no major outcome, whereas additional mutation to prevent proteolytic cleavage at the chloroplast membrane has a dramatic effect on virus infection.
authors.affiliation: USDA-ARS, USNA, Floral and Nursery Plants Research Unit, 10300 Baltimore Avenue, Beltsville, MD, USA.|Istituto di Virologia Vegetale CNR, Strada delle Cacce 73, 10135, Torino, Italy.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Vaira
authors.affiliation: Department of Applied Biology, Chungnam National University, Daejeon, 305-764, Republic of Korea.
authors.forename: Hyoun-Sub
authors.initials: HS
authors.lastname: Lim
authors.affiliation: USDA-ARS, PSI, Electron and Confocal Microscopy Unit, 10300 Baltimore Avenue, Beltsville, MD, USA.
authors.forename: Gary R
authors.initials: GR
authors.lastname: Bauchan
authors.affiliation: USDA-ARS, PSI, Molecular Plant Pathology Laboratory, 10300 Baltimore Avenue, Beltsville, MD, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Owens
authors.affiliation: USDA-ARS, PSI, Molecular Plant Pathology Laboratory, 10300 Baltimore Avenue, Beltsville, MD, USA.
authors.forename: Angela
authors.initials: A
authors.lastname: Natilla
authors.affiliation: USDA-ARS, USNA, Floral and Nursery Plants Research Unit, 10300 Baltimore Avenue, Beltsville, MD, USA.
authors.forename: Margaret M
authors.initials: MM
authors.lastname: Dienelt
authors.affiliation: USDA-ARS, USNA, Floral and Nursery Plants Research Unit, 10300 Baltimore Avenue, Beltsville, MD, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Reinsel
authors.affiliation: USDA-ARS, USNA, Floral and Nursery Plants Research Unit, 10300 Baltimore Avenue, Beltsville, MD, USA.
authors.forename: John
authors.initials: J
authors.lastname: Hammond
mesh_terms: D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D016254:Mutagenesis, Insertional; D009154:Mutation; D018515:Plant Leaves / Q000821:virology; D010942:Plant Viruses / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D011994:Recombinant Proteins; D014026:Nicotiana / Q000821:virology*; D017735:Virus Latency
chemical_list: D036022:Capsid Proteins; D018076:DNA, Complementary; D004279:DNA, Viral; D011994:Recombinant Proteins