In silico assessment of phosphorylation and O-β-GlcNAcylation sites in human NPC1 protein critical for Ebola virus entry

Infect Genet Evol. 2015 Aug:34:326-38. doi: 10.1016/j.meegid.2015.06.001. Epub 2015 Jun 3.

Abstract

Ebola is a highly pathogenic enveloped virus responsible for deadly outbreaks of severe hemorrhagic fever. It enters human cells by binding a multifunctional cholesterol transporter Niemann-Pick C1 (NPC1) protein. Post translational modification (PTM) information for NPC1 is crucial to understand Ebola virus (EBOV) entry and action due to changes in phosphorylation or glycosylation at the binding site. It is difficult and costly to experimentally assess this type of interaction, so in silico strategy was employed. Identification of phosphorylation sites, including conserved residues that could be possible targets for 21 predicted kinases was followed by interplay study between phosphorylation and O-β-GlcNAc modification of NPC1. Results revealed that only 4 out of 48 predicted phosphosites exhibited O-β-GlcNAc activity. Predicted outcomes were integrated with residue conservation and 3D structural information. Three Yin Yang sites were located in the α-helix regions and were conserved in studied vertebrate and mammalian species. Only one modification site S425 was found in β-turn region located near the N-terminus of NPC1 and was found to differ in pig, mouse, cobra and humans. The predictions suggest that Yin Yang sites may not be important for virus attachment to NPC1, whereas phosphosite 473 may be important for binding and hence entry of Ebola virus. This information could be useful in addressing further experimental studies and therapeutic strategies targeting PTM events in EBOV entry.

Keywords: Ebola; In silico; NPC1; Post translational modification.

MeSH terms

  • Amino Acid Sequence
  • Carrier Proteins / chemistry*
  • Carrier Proteins / metabolism
  • Computer Simulation
  • Conserved Sequence
  • Ebolavirus / physiology*
  • Glycosylation
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Membrane Glycoproteins / chemistry*
  • Membrane Glycoproteins / metabolism
  • Models, Molecular
  • Molecular Sequence Data
  • Niemann-Pick C1 Protein
  • Phosphorylation
  • Protein Binding
  • Protein Interaction Domains and Motifs
  • Protein Processing, Post-Translational*
  • Protein Structure, Secondary
  • Viral Envelope Proteins / chemistry
  • Virus Internalization*

Substances

  • Carrier Proteins
  • Intracellular Signaling Peptides and Proteins
  • Membrane Glycoproteins
  • NPC1 protein, human
  • Niemann-Pick C1 Protein
  • Viral Envelope Proteins