title: Murine hepatitis virus nsp4 N258T mutants are not temperature-sensitive.
abstract: Coronavirus replicase nsp4 is critical for virus-induced membrane modifications. An nsp4 mutant (N258T) of murine hepatitis virus (MHV) has been reported to be temperature-sensitive (ts) and to alter membrane targeting. We engineered and recovered all four possible codon variants of N258T in the cloned MHV-A59 background. All mutant viruses demonstrated impaired replication compared to wildtype MHV, but no nsp4 N258T mutant virus was ts, and all variants colocalized with viral protein markers for replication complexes, but not with markers for mitochondria. This study emphasizes that complete genome sequencing may be necessary, even with directed and confirmed reverse genetic mutants.
authors.affiliation: Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville, TN 37232, USA.
authors.forename: Dia C
authors.initials: DC
authors.lastname: Beachboard
authors.forename: Xiaotao
authors.initials: X
authors.lastname: Lu
authors.forename: Susan C
authors.initials: SC
authors.lastname: Baker
authors.forename: Mark R
authors.initials: MR
authors.lastname: Denison
mesh_terms: D000818:Animals; D002460:Cell Line; D051379:Mice; D006517:Murine hepatitis virus / Q000235:genetics* / Q000502:physiology; D009154:Mutation; D013696:Temperature; D017361:Viral Nonstructural Proteins / Q000235:genetics*; D014779:Virus Replication
chemical_list: D017361:Viral Nonstructural Proteins