Characterization of the arenavirus RING finger Z protein regions required for Z-mediated inhibition of viral RNA synthesis.
The prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) is an enveloped virus with a bisegmented negative-strand RNA genome whose proteomic capability is limited to four polypeptides, namely, nucleoprotein; surface glycoprotein (GP), which is proteolytically processed into GP1 and GP2; polymerase (L); and a small (11-kDa) RING finger protein (Z). Using a reverse genetic system based on the ARM strain of LCMV, we have previously shown that Z has a strong inhibitory activity on LCMV minigenome transcription and RNA replication (T. I. Cornu and J. C. de la Torre, J. Virol. 75:9415-9426, 2001). In the present study, we have identified regions and specific amino acid residues within Z which contribute to its inhibitory activity on RNA synthesis mediated by the LCMV polymerase. Z proteins from different LCMV strains had similar inhibitory activities on the expression of the LCMV ARM minigenome, whereas the Z protein of the genetically more distantly related Tacaribe virus had an approximately 10-fold lower inhibitory activity on ARM minigenome expression. Results from the use of chimera proteins between Z and Xenopus Neuralized, a nonviral RING finger protein, indicated that the structural integrity of the Z RING domain (RD) was required but not sufficient for the inhibitory activity of Z. Serial deletion mutants of the N and C termini of Z showed that the N terminus (residues 1 through 16) and C terminus (residues 79 through 90) do not contribute to the Z inhibitory activity. A highly conserved tryptophan (W) residue located at position 36 in ARM-Z, next to the second conserved cysteine (C) residue of the Z RD, also contributed to the Z inhibitory activity.
Cornu
Tatjana I
TI
Division of Virology, Department of Neuropharmacology, The Scripps Research Institute, 10550 N Torrey Pines Road, La Jolla, CA 92037, USA.
de la Torre
Juan Carlos
JC
D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D006224:Cricetinae; D016679:Genome, Viral; D047908:Intracellular Signaling Peptides and Proteins; D008217:Lymphocytic choriomeningitis virus / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000096:biosynthesis*; D012324:RNA-Dependent RNA Polymerase / Q000378:metabolism; D014158:Transcription, Genetic; D014779:Virus Replication; D016335:Zinc Fingers
D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D012367:RNA, Viral; C117526:p11 Z protein, Lymphocytic choriomeningitis virus; D012324:RNA-Dependent RNA Polymerase