title: Analysis of the retrovirus capsid interdomain linker region.
abstract: In structural studies, the retrovirus capsid interdomain linker region has been shown as a flexible connector between the CA N-terminal domain and its C-terminal domain. To analyze the function of the linker region, we have examined the effects of three Moloney murine leukemia virus (M-MuLV) capsid linker mutations/variations in vivo, in the context of the full-length M-MuLV structural precursor protein (PrGag). Two mutations, A1SP and A5SP, respectively, inserted three and seven additional codons within the linker region to test the effects of increased linker lengths. The third variant, HIV/Mo, represented a chimeric HIV-1/M-MuLV PrGag protein, fused at the linker region. When expressed in cells, the three variants reduced the efficiency of virus particle assembly, with PrGag proteins and particles accumulating at the cellular plasma membranes. Although PrGag recognition of viral RNA was not impaired, the capsid linker variant particles were abnormal, with decreased stabilities, anomalous densities, and aberrant multiple lobed and tubular morphologies. Additionally, rather than crosslinking as PrGag dimers, particle-associated A1SP, A5SP, and HIV/Mo proteins showed an increased propensity to crosslink as trimers. Our results suggest that a wild-type retrovirus capsid linker region is required for the proper alignment of capsid protein domains.
authors.affiliation: Vollum Institute and Department of Microbiology, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97201-3098, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Arvidson
authors.forename: Joshua
authors.initials: J
authors.lastname: Seeds
authors.forename: Mike
authors.initials: M
authors.lastname: Webb
authors.forename: Liam
authors.initials: L
authors.lastname: Finlay
authors.forename: Eric
authors.initials: E
authors.lastname: Barklis
mesh_terms: D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002213:Capsid / Q000737:chemistry*; D036022:Capsid Proteins / Q000235:genetics*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003062:Codon; D015683:Gene Products, gag / Q000235:genetics / Q000378:metabolism; D014644:Genetic Variation; D015497:HIV-1 / Q000737:chemistry / Q000235:genetics; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D008979:Moloney murine leukemia virus / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D016254:Mutagenesis, Insertional; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic; D016415:Sequence Alignment; D014779:Virus Replication
chemical_list: D036022:Capsid Proteins; D003062:Codon; D015683:Gene Products, gag; D011498:Protein Precursors