Novel gene product of Thogoto virus segment 6 codes for an interferon antagonist.
Thogoto virus (THOV) is a tick-transmitted orthomyxovirus with a genome of six negative-stranded RNA segments. The sixth segment encodes two different transcripts: a spliced transcript that is translated into the matrix protein (M) and an unspliced transcript. Here, we report that the unspliced transcript encodes an elongated form of M named ML. A THOV isolate deficient in ML expression was an efficient interferon inducer, whereas ML-expressing wild-type strains were poor interferon inducers. These results were confirmed with recombinant THOVs rescued from cDNAs. Expression of ML efficiently suppressed activation of the beta interferon promoter by double-stranded RNA. These results indicate that ML is an accessory protein that functions as a potent interferon antagonist by blocking transcriptional activation of alpha/beta interferons.
Hagmaier
Kathrin
K
Abteilung Virologie, Institut für Medizinische Mikrobiologie und Hygiene, Universität Freiburg, D-79008 Freiburg, Germany.
Jennings
Stephanie
S
Buse
Johanna
J
Weber
Friedemann
F
Kochs
Georg
G
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D006801:Humans; D016898:Interferon-alpha / Q000037:antagonists & inhibitors*; D016899:Interferon-beta / Q000037:antagonists & inhibitors*; D008969:Molecular Sequence Data; D012333:RNA, Messenger; D018117:Thogotovirus / Q000145:classification / Q000235:genetics / Q000276:immunology*; D014763:Viral Matrix Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
D016898:Interferon-alpha; D012333:RNA, Messenger; D014763:Viral Matrix Proteins; D016899:Interferon-beta