Localization of the N-terminal domain of cauliflower mosaic virus coat protein precursor.
Cauliflower mosaic virus (CaMV) open reading frame (ORF) IV encodes a coat protein precursor (pre-CP) harboring an N-terminal extension that is cleaved off by the CaMV-encoded protease. In transfected cells, pre-CP is present in the cytoplasm, while the processed form (p44) of CP is targeted to the nucleus, suggesting that the N-terminal extension might be involved in keeping the pre-CP in the cytoplasm for viral assembly. This study reports for the first time the intracellular localization of the N-terminal extension during CaMV infection in Brassica rapa. Immunogold-labeling electron microscopy using polyclonal antibodies directed to the N-terminal extension of the pre-CP revealed that this region is closely associated with viral particles present in small aggregates, which we called small bodies, adjacent to the main inclusion bodies typical of CaMV infection. Based on these results, we propose a model for viral assembly of CaMV.
Champagne
Julie
J
Centre de Recherche en Infectiologie, CHUQ, Pavillon CHUL, Quebec, Canada G1V 4G2. julie.champagne@crchul.ulaval.ca
Benhamou
Nicole
N
Leclerc
Denis
D
D029741:Brassica rapa / Q000648:ultrastructure / Q000821:virology*; D036022:Capsid Proteins / Q000378:metabolism*; D017796:Caulimovirus / Q000378:metabolism*; D003593:Cytoplasm / Q000821:virology; D007150:Immunohistochemistry; D002479:Inclusion Bodies / Q000821:virology; D016253:Microscopy, Immunoelectron; D010935:Plant Diseases / Q000821:virology; D018515:Plant Leaves / Q000648:ultrastructure / Q000821:virology; D011498:Protein Precursors / Q000032:analysis / Q000378:metabolism*; D019065:Virus Assembly
D036022:Capsid Proteins; D011498:Protein Precursors