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Constant and variable regions of measles virus proteins encoded by the nucleocapsid and phosphoprotein genes derived
K Baczko1, I Pardowitz, B K Rima
1Institute of Virology, University of Würzburg, Germany.
Abstract:
The nucleotide sequences of the N and P genes of two wild type measles virus strains JM and CM in two distinct lineages of the virus have been analyzed and compared with those of other MV strains in order to assess which parts of the internal proteins are variable. Most variations in the P protein appear to occur in the N-terminus, while the middle part of the protein (residues 201-350) and the C-terminus are conserved. The C protein varies primarily in its N-terminal amino acids. The C-terminal amino acid residues of the V protein, which are unique to this protein, do not vary significantly between measles virus strains. The data show that evolutionary trees determined on the basis of the N, P, or M genes are the same and that probably no recombination has taken place between these genes in the strains investigated so far. The M protein appears to be less variable than the other genes and thus changes observed in this gene in some SSPE and MIBE viruses may be of greater significance than were assumed earlier.
Insights
Analysis of measles virus (MV) genes reveals conserved regions in internal proteins, aiding evolutionary studies. The matrix (M) protein
Area of Science:
- Virology
- Molecular Biology
- Genetics
Background:
- Measles virus (MV) is a significant human pathogen.
- Understanding the genetic variability of MV is crucial for tracking its evolution and for developing effective vaccines and therapies.
- Internal proteins, including Nucleoprotein (N), Phosphoprotein (P), Matrix (M), and others like C and V, play vital roles in the MV life cycle.
Purpose of the Study:
- To analyze and compare the nucleotide sequences of the N and P genes from two wild-type measles virus strains (JM and CM).
- To assess the variability within specific regions of MV internal proteins (N, P, C, V, and M).
- To evaluate the evolutionary relationships between different MV strains based on N, P, and M genes and investigate potential recombination events.
Main Methods:
- Nucleotide sequence analysis of N and P genes from wild-type measles virus strains JM and CM.
- Comparative sequence analysis with other known MV strains.
- Phylogenetic analysis to construct evolutionary trees based on N, P, and M genes.
- Identification of conserved and variable regions within the analyzed viral proteins.
Main Results:
- Most variations in the P protein are located in the N-terminus, with conserved middle (residues 201-350) and C-terminal regions.
- The C protein shows variability primarily in its N-terminal amino acids.
- The C-terminal residues of the V protein, unique to this protein, exhibit minimal variation across MV strains.
- Evolutionary trees derived from N, P, and M genes are congruent, suggesting a lack of recombination among these genes in the studied strains.
- The M protein demonstrates lower variability compared to other genes, indicating that observed changes in M in SSPE and MIBE viruses might be more significant than previously thought.
Conclusions:
- Specific regions within measles virus internal proteins (P, C, V) exhibit distinct patterns of variability and conservation.
- The genetic data support the stability of evolutionary relationships based on N, P, and M genes, with no evidence of recombination.
- The lower variability of the M protein suggests its potential utility as a marker for significant viral evolution or adaptation events, particularly in disease contexts like SSPE and MIBE.