Herpes simplex viruses activate phospholipid scramblase to redistribute phosphatidylserines and Akt to the outer leaflet of the plasma membrane and promote viral entry

PLoS Pathog. 2018 Jan 2;14(1):e1006766. doi: 10.1371/journal.ppat.1006766. eCollection 2018 Jan.

Abstract

Herpes simplex virus (HSV) entry is associated with Akt translocation to the outer leaflet of the plasma membrane to promote a complex signaling cascade. We hypothesized that phospholipid scramblase-1 (PLSCR1), a calcium responsive enzyme that flips phosphatidylserines between membrane leaflets, might redistribute Akt to the outside during entry. Confocal imaging, biotinylation of membrane proteins and flow cytometric analysis demonstrated that HSV activates PLSCR1 and flips phosphatidylserines and Akt to the outside shortly following HSV-1 or HSV-2 exposure. Translocation was blocked by addition of a cell permeable calcium chelator, pharmacological scramblase antagonist, or transfection with small interfering RNA targeting PLSCR1. Co-immunoprecipitation and proximity ligation studies demonstrated that PLSCR1 associated with glycoprotein L at the outer leaflet and studies with gL deletion viruses indicate that this interaction facilitates subsequent restoration of the plasma membrane architecture. Ionomycin, a calcium ionophore, also induced PLSCR1 activation resulting in Akt externalization, suggesting a previously unrecognized biological phenomenon.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Biological Transport / drug effects
  • Calcium Ionophores / pharmacology
  • Cell Line
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism*
  • Cell Membrane / virology
  • Chlorocebus aethiops
  • Gene Deletion
  • Green Fluorescent Proteins / chemistry
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Humans
  • Phosphatidylserines / metabolism*
  • Phospholipid Transfer Proteins / agonists
  • Phospholipid Transfer Proteins / antagonists & inhibitors
  • Phospholipid Transfer Proteins / genetics
  • Phospholipid Transfer Proteins / metabolism*
  • Protein Transport / drug effects
  • Proto-Oncogene Proteins c-akt / metabolism*
  • RNA Interference
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Simplexvirus / drug effects
  • Simplexvirus / physiology*
  • Surface Properties / drug effects
  • Up-Regulation* / drug effects
  • Viral Envelope Proteins / genetics
  • Viral Envelope Proteins / metabolism
  • Virus Internalization* / drug effects

Substances

  • Calcium Ionophores
  • PLSCR1 protein, human
  • Phosphatidylserines
  • Phospholipid Transfer Proteins
  • Recombinant Fusion Proteins
  • Viral Envelope Proteins
  • glycoprotein L, Human herpesvirus 1
  • Green Fluorescent Proteins
  • Proto-Oncogene Proteins c-akt