Characterization and intracellular trafficking of Epstein-Barr virus BBLF1, a protein involved in virion maturation

J Virol. 2012 Sep;86(18):9647-55. doi: 10.1128/JVI.01126-12. Epub 2012 Jun 27.

Abstract

Epstein-Barr virus (EBV) BBLF1 shares 13 to 15% amino acid sequence identities with the herpes simplex virus 1 UL11 and cytomegalovirus UL99 tegument proteins, which are involved in the final envelopment during viral maturation. This study demonstrates that BBLF1 is a myristoylated and palmitoylated protein, as are UL11 and UL99. Myristoylation of BBLF1 both facilitates its membrane anchoring and stabilizes it. BBLF1 is shown to localize to the trans-Golgi network (TGN) along with gp350/220, a site where final envelopment of EBV particles takes place. The localization of BBLF1 at the TGN requires myristoylation and two acidic clusters, which interact with PACS-1, a cytosolic protein, to mediate retrograde transport from the endosomes to the TGN. Knockdown of the expression of BBLF1 during EBV lytic replication reduces the production of virus particles, demonstrating the requirement of BBLF1 to achieve optimal production of virus particles. BBLF1 is hypothesized to facilitate the budding of tegumented capsid into glycoprotein-embedded membrane during viral maturation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Biological Transport, Active
  • DNA, Viral / genetics
  • Gene Knockdown Techniques
  • HEK293 Cells
  • Herpesvirus 4, Human / genetics
  • Herpesvirus 4, Human / pathogenicity
  • Herpesvirus 4, Human / physiology*
  • Host-Pathogen Interactions / genetics
  • Host-Pathogen Interactions / physiology
  • Humans
  • Lipoylation
  • Molecular Sequence Data
  • Myristic Acid / chemistry
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Vesicular Transport Proteins / metabolism
  • Viral Proteins / chemistry
  • Viral Proteins / genetics
  • Viral Proteins / physiology*
  • Virus Replication
  • trans-Golgi Network / virology

Substances

  • DNA, Viral
  • PACS1 protein, human
  • Recombinant Fusion Proteins
  • Vesicular Transport Proteins
  • Viral Proteins
  • Myristic Acid