Frog virus 3 ORF 53R, a putative myristoylated membrane protein, is essential for virus replication in vitro.
Although previous work identified 12 complementation groups with possible roles in virus assembly, currently only one frog virus 3 protein, the major capsid protein (MCP), has been linked with virion formation. To identify other proteins required for assembly, we used an antisense morpholino oligonucleotide to target 53R, a putative myristoylated membrane protein, and showed that treatment resulted in marked reductions in 53R levels and a 60% drop in virus titers. Immunofluorescence assays confirmed knock down and showed that 53R was found primarily within viral assembly sites, whereas transmission electron microscopy detected fewer mature virions and, in some cells, dense granular bodies that may represent unencapsidated DNA-protein complexes. Treatment with a myristoylation inhibitor (2-hydroxymyristic acid) resulted in an 80% reduction in viral titers. Collectively, these data indicate that 53R is an essential viral protein that is required for replication in vitro and suggest it plays a critical role in virion formation.
Whitley
Dexter S
DS
Department of Microbiology, University of Mississippi Medical Center, Jackson, MS 39216, USA.
Yu
Kwang
K
Sample
Robert C
RC
Sinning
Allan
A
Henegar
Jeffrey
J
Norcross
Erin
E
Chinchar
V Gregory
VG
D000818:Animals; D002460:Cell Line; D005455:Fluorescent Antibody Technique; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D019814:Myristic Acid / Q000378:metabolism; D016376:Oligonucleotides, Antisense; D016366:Open Reading Frames / Q000235:genetics / Q000502:physiology*; D017995:Ranavirus / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D014771:Virion / Q000378:metabolism; D019065:Virus Assembly; D014779:Virus Replication
D008565:Membrane Proteins; D016376:Oligonucleotides, Antisense; D014764:Viral Proteins; D019814:Myristic Acid