Regulation of coronavirus RNA transcription is likely mediated by protein-RNA interactions.
Coronavirus mRNA transcription was thought to be regulated by the interaction between the leader RNA and the intergenic (IG) sequence, probably involving direct RNA-RNA interactions between complementary sequences. In this study, we found that a 9-nucleotide sequence immediately downstream of the leader RNA up-regulated mRNA transcription and that a particular strain of mouse hepatitis virus (MHV) lacking this 9-nucleotide transcribed subgenomic mRNA species containing unusually heterogeneous leader-fusion sites. These results suggest that the sequence complementarity between the leader and IG is not necessarily required for mRNA transcription. UV cross-linking experiments using cytoplasmic extracts of uninfected cells and the IG sequence showed that three different cellular proteins bound to IG of the template RNA. Deletion analyses and site-directed mutagenesis of IG further demonstrated a correlation between protein-binding and transcription efficiency, suggesting that these RNA-binding proteins are involved in the regulation of coronavirus mRNA transcription. We propose that coronavirus transcription is regulated by RNA-protein and protein-protein interactions.
Zhang
X M
XM
Department of Neurology, University of Southern California School of Medicine, Los Angeles, USA.
Lai
M M
MM
D000818:Animals; D001483:Base Sequence; D015967:Gene Expression Regulation, Viral; D007438:Introns; D051379:Mice; D008969:Molecular Sequence Data; D006517:Murine hepatitis virus / Q000235:genetics* / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000378:metabolism; D012367:RNA, Viral / Q000096:biosynthesis / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012091:Repetitive Sequences, Nucleic Acid; D017384:Sequence Deletion; D014158:Transcription, Genetic; D014162:Transfection
D012333:RNA, Messenger; D012367:RNA, Viral; D016601:RNA-Binding Proteins