Involvement of cardiovirus leader in host cell-restricted virus expression.
Theiler murine encephalomyelitis virus designates a number of picornavirus strains that are classified into two subgroups on the basis of their different biological activities. DA strain and other members of the TO subgroup produce a chronic demyelinating disease in which the virus persists and manifests a restricted expression. Mutagenesis studies of the DA strain leader (L) coding region, which is located at the 5' end of the polyprotein coding region, demonstrate that L is completely dispensable for infection of some cells; in addition, nucleotides can be inserted into the L coding region with no loss in infectivity, indicating that Theiler murine encephalomyelitis virus may be used as a vector for delivering foreign sequences. In other cells, L is critical for plaque formation and efficient viral multiplication. These findings raise the possibility that L may play a role in the DA-induced demyelinating restricted infection. The functions of L, and even its presence within the genome, vary among picornaviruses, reflecting the various requirements for viral growth among different host cells.
Kong
W P
WP
Department of Neurology, University of Chicago Medical Center, IL 60637.
Ghadge
G D
GD
Roos
R P
RP
D000595:Amino Acid Sequence; D000818:Animals; D018188:Cardiovirus Infections / Q000209:etiology; D002460:Cell Line; D006224:Cricetinae; D003711:Demyelinating Diseases / Q000209:etiology; D005814:Genes, Viral; D004680:Maus Elberfeld virus / Q000235:genetics* / Q000472:pathogenicity; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D021382:Protein Sorting Signals / Q000235:genetics*; D014158:Transcription, Genetic; D014162:Transfection; D014764:Viral Proteins / Q000235:genetics*
D021382:Protein Sorting Signals; D014764:Viral Proteins