Evidence of trem2 variant associated with triple risk of Alzheimer's disease

PLoS One. 2014 Mar 24;9(3):e92648. doi: 10.1371/journal.pone.0092648. eCollection 2014.

Abstract

Alzheimer's disease is one of the main causes of dementia among elderly individuals and leads to the neurodegeneration of different areas of the brain, resulting in memory impairments and loss of cognitive functions. Recently, a rare variant that is associated with 3-fold higher risk of Alzheimer's disease onset has been found. The rare variant discovered is a missense mutation in the loop region of exon 2 of Trem2 (rs75932628-T, Arg47His). The aim of this study was to investigate the evidence for potential structural and functional significance of Trem2 gene variant (Arg47His) through molecular dynamics simulations. Our results showed the alteration caused due to the variant in TREM2 protein has significant effect on the ligand binding affinity as well as structural configuration. Based on molecular dynamics (MD) simulation under salvation, the results confirmed that native form of the variant (Arg47His) might be responsible for improved compactness, hence thereby improved protein folding. Protein simulation was carried out at different temperatures. At 300K, the deviation of the theoretical model of TREM2 protein increased from 2.0 Å at 10 ns. In contrast, the deviation of the Arg47His mutation was maintained at 1.2 Å until the end of the simulation (t = 10 ns), which indicated that Arg47His had reached its folded state. The mutant residue was a highly conserved region and was similar to "immunoglobulin V-set" and "immunoglobulin-like folds". Taken together, the result from this study provides a biophysical insight on how the studied variant could contribute to the genetic susceptibility to Alzheimer's disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / genetics*
  • Amino Acid Sequence
  • Amino Acid Substitution
  • Computational Biology
  • Genetic Predisposition to Disease / genetics*
  • Humans
  • Membrane Glycoproteins / chemistry
  • Membrane Glycoproteins / genetics*
  • Membrane Glycoproteins / metabolism
  • Molecular Dynamics Simulation
  • Molecular Sequence Data
  • Mutation, Missense*
  • Phenotype
  • Point Mutation
  • Polymorphism, Single Nucleotide
  • Protein Stability
  • Protein Structure, Tertiary
  • Receptors, Immunologic / chemistry
  • Receptors, Immunologic / genetics*
  • Receptors, Immunologic / metabolism
  • Solvents / chemistry
  • Thermodynamics

Substances

  • Membrane Glycoproteins
  • Receptors, Immunologic
  • Solvents
  • TREM2 protein, human

Grants and funding

The authors extend their appreciation to the Deanship of Scientific Research at King Saud University for funding this work through the research group project No: RGP-VPP-200. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.