title: Identification of a dominant negative inhibitor of human zinc finger antiviral protein reveals a functional endogenous pool and critical homotypic interactions.
abstract: The zinc finger antiviral protein (ZAP) is a host factor with potent antiviral activity when overexpressed in cells. ZAP blocks replication of the prototype alphavirus Sindbis virus (SINV) at a step at or before translation of the incoming viral genome. The mechanism of ZAP anti-SINV activity and the determinants of its antiviral function, however, have not been defined. Here, we have identified a dominant negative inhibitor of human ZAP. Rat ZAP with a cysteine-to-arginine mutation at position 88 (rZAPC88R), previously reported as a nonfunctional form of ZAP, increases SINV growth in cells. These results led us to discover a previously undetectable pool of endogenous functional ZAP within human cells. Investigation of the mechanism of dominant negative inhibition, combined with a comprehensive mutational analysis of the antiviral factor, revealed that homotypic associations are required for ZAP function in limiting SINV propagation.
authors.affiliation: Laboratory of Virology and Infectious Disease, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA.
authors.forename: Lok Man J
authors.initials: LM
authors.lastname: Law
authors.forename: Owen R
authors.initials: OR
authors.lastname: Albin
authors.forename: John-William N
authors.initials: JW
authors.lastname: Carroll
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Jones
authors.forename: Charles M
authors.initials: CM
authors.lastname: Rice
authors.forename: Margaret R
authors.initials: MR
authors.lastname: Macdonald
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics* / Q000494:pharmacology*; D002460:Cell Line; D002478:Cells, Cultured; D006224:Cricetinae; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D050505:Mutant Proteins / Q000235:genetics* / Q000494:pharmacology*; D020125:Mutation, Missense; D011485:Protein Binding; D016601:RNA-Binding Proteins / Q000037:antagonists & inhibitors*; D051381:Rats; D012845:Sindbis Virus / Q000254:growth & development* / Q000276:immunology; D019562:Viral Load
chemical_list: D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D050505:Mutant Proteins; D016601:RNA-Binding Proteins; C527496:ZC3HAV1 protein, human; C465959:Zc3hav1 protein, rat