The alternate triad motif of the poly(ADP-ribose) polymerase-like domain of the human zinc finger antiviral protein is essential for its antiviral activity.
The human zinc finger antiviral protein (hZAP) gene is spliced to yield a short (hZAP-S) and a long (hZAP-L) isoform. The long isoform possesses a poly(ADP-ribose) polymerase (PARP)-like domain in its C-terminus predicted to be inactive due to alterations in its triad motif compared with bona fide PARPs. Using Sindbis virus as prototype member of alphaviruses we confirmed that hZAP-L is a more potent inhibitor of alphaviruses than hZAP-S. Specific small interfering RNA knockdown of hZAP-L but not hZAP-S demonstrated a role of endogenous hZAP-L in restriction of alphavirus replication. Whilst single amino-acid substitutions in the triad motif of hZAP-L's PARP-like domain reduced the antiviral activity, exchange of all three triad motif residues to alanine or to the amino acids of active PARPs virtually abolished the antiviral effect. Contrary to previous assumptions, these results indicate an essential function of the PARP-like domain in hZAP-L's antiviral activity.
Institute of Virology, University of Bonn Medical Center, Bonn, Germany.
Sabine
S
Gläsker
Institute of Virology, University of Bonn Medical Center, Bonn, Germany.
Maren
M
Töller
Institute of Virology, University of Bonn Medical Center, Bonn, Germany.
Beate Mareike
BM
Kümmerer
D019943:Amino Acid Substitution; D000998:Antiviral Agents / Q000378:metabolism*; D002460:Cell Line; D002470:Cell Survival; D004252:DNA Mutational Analysis; D006801:Humans; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D012845:Sindbis Virus / Q000276:immunology*; D019562:Viral Load; D014779:Virus Replication / Q000276:immunology*
D000998:Antiviral Agents; D050505:Mutant Proteins; D016601:RNA-Binding Proteins; C527496:ZC3HAV1 protein, human; D011065:Poly(ADP-ribose) Polymerases