Matrix Protein of Cell-associated Subacute Sclerosing Panencephalitis Viruses

Abstract

SUMMARYThe nucleotide sequence has been determined for the matrix (M) protein gene of three strains, Niigata-1, ZH and Biken, of cell-associated subacute sclerosing panencephalitis (SSPE) virus. The M proteins of the Niigata-1 and ZH strains were found to terminate prematurely as a result of nonsense mutations at nucleotide positions 68 and 96 respectively. On the other hand it was predicted that the Biken strain would express M protein with 22 amino acid differences and eight additional amino acids at its C terminus in comparison to the M protein of the Edmonston strain of measles virus. Radiolabelling of cells carrying the Biken strain showed the production of an M protein with considerably altered immunoreactivity and a marked reduction in intracellular stability. Either premature termination or rapid degradation of the M protein may underlie the defectiveness of these three strains of SSPE virus.

The matrix proteins of neurovirulent subacute sclerosing panencephalitis virus and its acute measles virus progenitor are functionally different.

“…The nucleotide sequences of acute MV and SSPE virus strains differ at numerous positions (4). The genetic differences are often manifested as abnormalities in the expression, structure, or stability of the matrix (M), fusion (F), or hemagglutinin (H) protein (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). These abnormalities are thought to be responsible for the nonproductive mode of SSPE virus infection.…”

Identification of Several Different Lineages of Measles Virus

“…However, analysis of the ability of different strains of the virus to bind monoclonal antibodies has revealed a low level of variability in the major antigens (Sheshberadaran et al, 1983) and, more recently, strain variations have been studied directly by analysis of the nucleotide sequences of MV strains (data compiled in Cattaneo et al, 1989). Most data are available for the matrix protein (M) gene of MV where a number of lytic growing strains (Bellini et al, 1986, Wong et al, 1987Curran & Rima, 1988) and subacute sclerosing parencephalitis (SSPE)-derived strains (compiled in Cattaneo et al, 1989;Enami et al, 1989) have been analysed. This gene has been studied in detail because it has been assumed that it, in particular, is defectively expressed in SSPE.…”

Full‐Length Sequence Analysis of Subacute Sclerosing Panencephalitis (SSPE) Virus, a Mutant of Measles Virus, Isolated from Brain Tissues of a Patient Shortly after Onset of SSPE

“…some SSPE virus strains have mutations that drastically alter the structure of the M protein, due to the lack of the normal initiation codon with the usage of an alternative initiation codon and alternative termination codons (3,14,20). Our study has revealed that the M protein of SSPE-Kobe-1 has the authentic N-and C-termini.…”