Rift Valley fever virus noncoding regions of L, M and S segments regulate RNA synthesis.
Rift Valley fever virus (RVFV) (Phlebovirus, Bunyaviridae) possesses a genome composed of three negative-stranded RNA molecules. Each segment contains 3' and 5' noncoding regions with terminal complementary sequences forming a panhandle structure. We showed that transcription-replication of the L, M and S segments is regulated, and we established a minigenome rescue system expressing a CAT reporter to investigate the role of the noncoding regions in this process. The L, M and S segment-based minigenomes were shown to drive bona fide transcription and replication and to express variable levels of CAT reporter, indicating differential promoter activities within the noncoding sequences. In addition, we found a good correlation between the relative promoter strength and the abundance of viral RNA species in RVFV-infected cells. Altogether, these results show that RVFV minigenomes are powerful tools to study transcription and replication and constitute a valuable basis to rescue infectious virus from cDNAs.
Gauliard
Nicolas
N
Institut Pasteur, Unité de Génétique Moléculaire des Bunyaviridés, 25 rue du Dr Roux 75724 Paris cedex 15, France.
Billecocq
Agnès
A
Flick
Ramon
R
Bouloy
Michèle
M
D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D021901:DNA, Intergenic / Q000235:genetics*; D015967:Gene Expression Regulation, Viral; D016679:Genome, Viral; D012367:RNA, Viral / Q000096:biosynthesis* / Q000235:genetics*; D012296:Rift Valley fever virus / Q000235:genetics*; D014158:Transcription, Genetic / Q000235:genetics*
D021901:DNA, Intergenic; D012367:RNA, Viral