title: A temperature-sensitive mutant of Newcastle disease virus which is affected in both haemagglutinin-neuraminidase and matrix proteins.
abstract: Virions prepared from a non-revertible temperature-sensitive (ts) mutant (ts53) of Newcastle disease virus (NDV) grown in ovo at the permissive temperature (34 degrees C) possessed thermolabile haemagglutination and neuraminidase activities compared with parental (ts+) virions. Purified haemagglutinin-neuraminidase (HN) protein from ts53 virions was also more thermolabile than ts+ HN protein. SDS-PAGE analysis of [3H]leucine pulse- and pulse/chase-labelled NDV proteins synthesized in chick embryo fibroblasts following infection with ts+ and ts53 virus revealed that ts53 matrix (M) protein was unstable and disappeared during chase incubations only at the non-permissive temperature (42 degrees C). The non-revertibility of the ts53 mutant may indicate that it is a double mutant affected in both HN and M genes; alternatively this mutant may only be affected in the HN gene, the close physical association of the thermolabile HN with the M protein during virus maturation resulting in the lack of protection of the M protein from the action of cellular proteases at the non-permissive temperature.
mesh_terms: D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D005814:Genes, Viral; D006389:Hemagglutinins, Viral / Q000235:genetics*; D009154:Mutation; D009439:Neuraminidase / Q000235:genetics*; D009522:Newcastle disease virus / Q000032:analysis / Q000235:genetics*; D013696:Temperature; D014763:Viral Matrix Proteins; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D006389:Hemagglutinins, Viral; D014763:Viral Matrix Proteins; D014764:Viral Proteins; D003609:Dactinomycin; D003513:Cycloheximide; D009439:Neuraminidase