The open reading frame 3 gene of hepatitis E virus contains a cis-reactive element and encodes a protein required for infection of macaques.
An infectious cDNA clone of hepatitis E virus was mutated in order to prevent synthesis of either open reading frame 2 (ORF2) protein or ORF3 protein. HuH-7 cells transfected with an ORF2-null mutant produced ORF3, and those transfected with an ORF3-null mutant produced ORF2. Silent mutations introduced into a highly conserved nucleotide sequence in the ORF3 coding region eliminated the synthesis of both ORF2 and ORF3 proteins, suggesting that it comprised a cis-reactive element. A mutant that was not able to produce ORF3 protein did not produce a detectable infection in rhesus macaques. However, a mutant that encoded an ORF3 protein lacking a phosphorylation site reported to be critical for function was able to replicate its genome in cell culture and to induce viremia and seroconversion in rhesus monkeys, suggesting that phosphorylation of ORF3 protein was not necessary for genome replication or for production of infectious virions.
Graff
Judith
J
Molecular Hepatitis Section, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892-8009, USA.
Nguyen
Hanh
H
Yu
Claro
C
Elkins
William R
WR
St Claire
Marisa
M
Purcell
Robert H
RH
Emerson
Suzanne U
SU
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D018076:DNA, Complementary / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D016368:Frameshift Mutation; D005814:Genes, Viral; D016752:Hepatitis E virus / Q000235:genetics* / Q000472:pathogenicity* / Q000502:physiology; D006801:Humans; D008253:Macaca mulatta; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames; D010766:Phosphorylation; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics; D014162:Transfection; D014764:Viral Proteins / Q000235:genetics / Q000502:physiology; D014774:Virulence / Q000235:genetics / Q000502:physiology; D014779:Virus Replication / Q000235:genetics / Q000502:physiology
D018076:DNA, Complementary; D004279:DNA, Viral; D012367:RNA, Viral; D014764:Viral Proteins