Capped small RNAs and MOV10 in human hepatitis delta virus replication.
The evolutionary origin of human hepatitis delta virus (HDV) replication by RNA-directed transcription is unclear. Here we identify two species of 5'-capped, approximately 18-25-nucleotide small RNAs. One was of antigenomic polarity, corresponding to the 5' end of hepatitis delta antigen (HDAg) mRNA, and interacted with HDAg and RNA polymerase II (Pol II), whereas the other mapped to a structurally analogous region on the genomic RNA hairpin. An HDAg-interaction screen indicated that HDAg interacts with MOV10, the human homolog of the Arabidopsis thaliana RNA amplification factor gene SDE3 and Drosophila melanogaster RISC-maturation factor gene Armitage (armi). MOV10 knockdown inhibited HDV replication, but not HDAg mRNA translation, further supporting a role for MOV10 in RNA-directed transcription. Together, our studies define RNA hairpins as critical elements for the initiation of HDV-related, RNA-directed transcription. The identification of capped small RNAs and the involvement of MOV10 in HDV replication further suggest a conserved mechanism related to RNA-directed transcription in lower eukaryotes.
Haussecker
Dirk
D
Department of Pediatrics, Stanford University, 300 Pasteur Dr., Stanford, California 94305, USA.
Cao
Dan
D
Huang
Yong
Y
Parameswaran
Poornima
P
Fire
Andrew Z
AZ
Kay
Mark A
MA
D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000378:metabolism; D016679:Genome, Viral / Q000235:genetics; D003698:Hepatitis Delta Virus / Q000235:genetics / Q000502:physiology*; D035923:Hepatitis delta Antigens / Q000378:metabolism; D006801:Humans; D006900:Hydroxylation; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D012315:RNA Caps / Q000378:metabolism*; D020365:RNA Helicases / Q000378:metabolism*; D034443:RNA Transport; D018075:RNA, Complementary / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D014779:Virus Replication / Q000502:physiology*
D004268:DNA-Binding Proteins; D035923:Hepatitis delta Antigens; D012315:RNA Caps; D018075:RNA, Complementary; D012333:RNA, Messenger; D012367:RNA, Viral; C530476:Mov10 protein, human; D020365:RNA Helicases