Disease relevance of NP

• The assembly of Ebola virus nucleocapsid requires virion-associated proteins 35 and 24 and posttranslational modification of nucleoprotein [1].
• At 739 amino acids, the nucleoprotein (NP) of Ebola virus is the largest nucleoprotein of the nonsegmented negative-stranded RNA viruses, and like the NPs of other viruses, it plays a central role in virus replication [2].
• NP was expressed as a His-tagged fusion protein in Escherichia coli and was purified on resins charged with nickel ions [3].
• The full-length EBOV NP and VP35 of the EBOV subtype Zaire were expressed as histidine-tagged recombinant proteins in the baculovirus expression system [4].
• A small region in the middle of the MBG and EBO NP sequences was found to contain a significant amino acid homology with NPs of paramyxoviruses and to a lesser extent with rhabdoviruses [5].

High impact information on NP

• We were unable to identify the types of glycosylation and sialylation, although we did confirm that Ebola virus NP was glycosylated [2].
• These data advance our understanding of the functional region(s) of Ebola virus NP, which in turn should improve our knowledge of the Ebola virus life cycle and its extreme pathogenicity [2].
• Here, we examined the glycosylation of Ebola virus NP and further investigated its properties by generating deletion mutants to define the region(s) involved in NP-NP interaction (self-assembly), in the formation of nucleocapsid-like structures, and in the replication of the viral genome [2].
• Vaccination induced both antibodies to the NP and a major histocompatibility complex class I-restricted CTL response to an 11-amino-acid sequence in the amino-terminal portion of the Ebola virus NP [6].
• Protection from Ebola virus mediated by cytotoxic T lymphocytes specific for the viral nucleoprotein [6].

Biological context of NP

• The nucleoprotein gene is located proximal to the 3' end of the genome and is preceeded by a putative leader sequence [7].
• An in vitro transcript, generated from plasmid DNA containing the entire coding region, directs the synthesis of authentic nucleoprotein in a rabbit reticulocyte lysate system [7].
• Two silent base changes were found in the open reading frame (ORF) encoding NP protein [8].
• Alignments of the entire NP amino acid sequences of these viruses also suggest that filoviruses are more closely related to paramyxoviruses than to rhabdoviruses [5].
• The 5' end of the NP mRNA was determined as was the polyadenylation site for the NP gene [5].

Anatomical context of NP

• HeLa cells abortively infected with the baculovirus expressed EBO NP, and this was used as an immunofluorescent (IF) antigen to detect EBO immunoglobulin G (IgG) antibody [9].
• Identification of murine T-cell epitopes in Ebola virus nucleoprotein [10].
• Analysis of linear B-cell epitopes of the nucleoprotein of ebola virus that distinguish ebola virus subtypes [11].

Associations of NP with chemical compounds

• Previous vaccine efforts with Ebola virus Zaire (EBOV-Z) emphasized the potential protective efficacies of immune responses to the surface glycoprotein and the nucleoprotein [12].

Other interactions of NP

• Peptide mapping of glycoproteins, nucleoproteins (NP) and viral structural protein (VP40) demonstrated extensive sequence conservation in the proteins of viruses isolated over a 13-year period, but homology was not evident in VP24 [13].
• Four antibodies reacting strongly with sGP and weakly with GP and two antibodies reacting with NP were not neutralizing [14].

Analytical, diagnostic and therapeutic context of NP

• To determine whether this earlier immune response could nonetheless protect against disease, cynomolgus macaques were challenged with Ebola virus after vaccination with ADV-GP and nucleoprotein (NP) vectors [15].
• In contrast, adoptive transfer of CTLs specific for the Ebola virus NP protected unvaccinated mice from lethal Ebola virus challenge [6].
• We developed an immunoglobulin G (IgG) ELISA using His-EBO-NP and the C-terminal halves of the NPs of EBO and MBG as antigens [16].
• Western-blot analysis showed that IgG responses were directed to nucleoprotein and viral protein of 40 kDa [17].
• Immunofluorescence method for detection of Ebola virus immunoglobulin g, using HeLa cells which express recombinant nucleoprotein [9].

References