Sequence analysis and editing of the phosphoprotein (P) gene of rinderpest virus

Functionalizing gold nanoparticles with bluetongue virus multiple peptide antigens utilizing gold-thiol interaction: a novel approach to develop pen side test

Bluetongue is an economically important viral disease of small ruminants. The present/current diagnostic kits and methods to diagnose BTV are laborious, time consuming and expensive. In the present study, we have attempted to develop a novel approach to detect BTV antibodies in sera that in future can be harnessed for developing a pen side diagnostic test. Briefly, we identified the immunodominant regions of the VP7 protein of BTV and synthesized them in the multiple antigenic peptide (MAP) format with cysteine at C-terminal of the lysine mosaic, which elicited highly ordered conformation as well as ELISA reactivity. Finally, we coated the MAP peptides on the gold nanoparticles that can be used to detect BTV specific antibodies in the sera using a spot test.

The Plowright vaccine strain of Rinderpest virus has attenuating mutations in most genes

The currently used vaccine strain of Rinderpest virus was derived by serial passage of the highly virulent Kabete ‘O’ strain (KO). A full-length cDNA copy of the KO strain was made from which a virus identical in pathogenicity to the wild-type virus was rescued. A series of chimeric viruses was prepared in which the coding sequences for the N, P, F, H or L proteins were replaced with the corresponding sequences from the vaccine strain. The KO-based virus with the vaccine strain H gene and that with the carboxy-terminal half of the L gene replaced with the corresponding sequence from the vaccine strain retained all or almost all of the virulence of the original KO virus. Animals infected with the KO-based virus containing the vaccine strain N, P or F gene, or the amino-terminal half of the L gene, developed high and prolonged pyrexia and leukopenia, but with reduced or absent lesions and other clinical signs; although partially attenuated, none was nearly as attenuated as the vaccine strain itself. These data indicate that the high attenuation and stability of the current vaccine are due to the accumulation of a number of separate mutations, none of which is itself so sufficiently debilitating that there is strong selective pressure in favour of the revertant.

Rinderpest virus C and V proteins interact with the major (L) component of the viral polymerase

Rinderpest virus, like other Morbilliviruses, expresses three proteins from the single P gene. In addition to the P protein, which interacts both with the viral polymerase (L) and the nucleocapsid (N) protein, the virus expresses a C and a V protein from the same gene. The functions of these two proteins in the viral life cycle are not clear. Although both C and V proteins are dispensable, in that viable viruses can be made that express neither, each seems to play a role in optimum viral replication. We have used the yeast-two hybrid system, binding to coexpressed fusions of C and V to glutathione-S-transferase, and studies of the native size of these proteins to investigate interactions of the rinderpest virus C and V proteins with other virus-encoded proteins. The V protein was found to interact with both the N and L proteins, while the C protein was found to bind to the L protein, and to self-associate in high-molecular-weight aggregates.

Complete genome sequence of transmissible gastroenteritis coronavirus PUR46-MAD clone and evolution of the purdue virus cluster

The complete sequence (28580 nt) of the PUR46-MAD clone of the Purdue cluster of transmissible gastroenteritis coronavirus (TGEV) has been determined and compared with members of this cluster and other coronaviruses. The computing distances among their S gene sequences resulted in the grouping of these coronaviruses into four clusters, one of them exclusively formed by the Purdue viruses. Three new potential sequence motifs with homology to the alpha-subunit of the polymerase-associated nucleocapsid phosphoprotein of rinderpest virus, the Bowman-Birk type of proteinase inhibitors, and the metallothionein superfamily of cysteine rich chelating proteins have been identified. Comparison of the TGEV polymerase sequence with that of other RNA viruses revealed high sequence homology with the A-E domains of the palm subdomain of nucleic acid polymerases.

Molecular evolution of the Paramyxoviridae and Rhabdoviridae multiple-protein-encoding P gene

Presented here is an analysis of the molecular evolutionary dynamics of the P gene among 76 representative sequences of the Paramyxoviridae and Rhabdoviridae RNA virus families. In a number of Paramyxoviridae taxa, as well as in vesicular stomatitis viruses of the Rhabdoviridae, the P gene encodes multiple proteins from a single genomic RNA sequence. These products include the phosphoprotein (P), as well as the C and V proteins. The complexity of the P gene makes it an intriguing locus to study from an evolutionary perspective. Amino acid sequence alignments of the proteins encoded at the P and N loci were used in independent phylogenetic reconstructions of the Paramyxoviridae and Rhabdoviridae families. P-gene-coding capacities were mapped onto the Paramyxoviridae phylogeny, and the most parsimonious path of multiple-coding-capacity evolution was determined. Levels of amino acid variation for Paramyxoviridae and Rhabdoviridae P-gene-encoded products were also analyzed. Proteins encoded in overlapping reading frames from the same nucleotides have different levels of amino acid variation. The nucleotide architecture that underlies the amino acid variation was determined in order to evaluate the role of selection in the evolution of the P gene overlapping reading frames. In every case, the evolution of one of the proteins encoded in the overlapping reading frames has been constrained by negative selection while the other has evolved more rapidly. The integrity of the overlapping reading frame that represents a derived state is generally maintained at the expense of the ancestral reading frame encoded by the same nucleotides. The evolution of such multicoding sequences is likely a response by RNA viruses to selective pressure to maximize genomic information content while maintaining small genome size. The ability to evolve such a complex genomic strategy is intimately related to the dynamics of the viral quasispecies, which allow enhanced exploration of the adaptive landscape.

Molecular cloning and sequence analysis of the phosphoprotein (P) gene of the lapinized rinderpest virus

We determined the nucleotide sequence of the coding region for the phosphoprotein (P) gene of the L strain of rinderpest virus (RPV). The gene encodes two overlapping open reading frames of 1521 and 531 nucleotides. Use of the first ATG would produce a P polypeptide of 507 amino acids, while use of the second ATG would produce a C polypeptide of 177 amino acids. In addition, the insertion of an extra G residue at the editing site generates an alternative mRNA potentially encoding the V protein of RPV. Homology comparisons of the P, C and V proteins among various viruses suggest that RPV is closer to measles virus (MV) than to canine distemper virus (CDV). Alignment of the sequences unique to the V protein revealed that the cysteine residues are well conserved among RPV, MV and CDV, and form a "zinc finger"-like motif.

Phosphorylation of canine distemper virus P protein by protein kinase C-zeta and casein kinase II

Transcription by nonsegmented negative-strand RNA viruses is mediated by the viral RNA-dependent RNA polymerase and transcriptional cofactor P. The P protein is activated by phosphorylation, an event initiated by cellular kinases. The kinase used differs among this group of RNA viruses; vesicular stomatitis virus and respiratory syncytial virus utilize casein kinase II (CKII), whereas human parainfluenza virus type 3 utilizes PKC isoform zeta (PKC-zeta) for activation of its P protein. To identify the cellular kinase(s) involved in the phosphorylation of the canine distemper virus (CDV) P protein, we used recombinant CDV P in phosphorylation assays with native kinase activities present in CV1 cell extracts or purified CKII and PKC isoforms. Here, we demonstrate that the CDV P protein is phosphorylated by two cellular kinases, where PKC-zeta has the major and CKII the minor activities. In contrast, the P protein of another member of the morbillivirus genus, measles virus, is phosphorylated predominantly by CKII, whereas PKC-zeta has only minor activity. Selective inhibition of PKC-zeta activity within CV1 cells eliminated permissiveness to CDV replication, indicating an in vivo role for PKC-zeta in the virus replication cycle. The broad tissue expression of PKC-zeta parallels the pantropic nature of CDV infections, suggesting that PKC-zeta activity is a determinant of cellular permissiveness to CDV replication.

Immunological responses of mice and cattle to baculovirus-expressed F and H proteins of rinderpest virus: lack of protection in the presence of neutralizing antibody

Rinderpest is a highly contagious viral disease of ruminants and has greater than 95% morbidity and mortality. The etiological agent, rinderpest virus (RPV), is a member of the family Paramyxoviridae and the genus Morbillivirus. Immune responses to both the hemagglutinin (H) and the fusion (F) antigens of morbilliviruses play an important role in the prevention of infection, and only attenuated live vaccines have been shown to provide protective immunity against the group. The lack of protection with inactivated vaccines has been attributed to the denaturation of the F glycoprotein of the virus. Our previous study, however, demonstrated complete protection of cattle vaccinated with infectious vaccinia virus recombinants expressing the H (vRVH) or F (vRVF) protein alone, even in the presence of only 4 U of serum-neutralizing (SN) antibody to RPV (T. Yilma, D. Hsu, L. Jones, S. Owens, M. Grubman, C. Mebus, M. Yamanaka, and B. Dale, Science 242:1058-1061, 1988). We have constructed recombinant baculoviruses that express the F (Fb) and H (Hb) glycoproteins of RPV. Furthermore, we have analyzed the immune responses of mice and cattle to these antigens. Cattle vaccinated with Fb or Hb or a mixture of both antigens were not protected from challenge inoculation with RPV, even when the SN titer was greater than in cattle vaccinated with vRVF alone. This lack of protection, in the presence of SN antibody, would indicate that live attenuated and recombinant vaccines induce immune responses necessary for protection (e.g., cell-mediated immunity) that are not generated by subunit or inactivated whole-virus vaccines.