Comparative proteomic analysis identifies age-dependent increases in the abundance of specific proteins after deletion of the small heat shock proteins αA- and αB-crystallin

Biochemistry. 2013 Apr 30;52(17):2933-48. doi: 10.1021/bi400180d. Epub 2013 Apr 16.

Abstract

Mice with deletion of genes for small heat shock proteins αA- and αB-crystallin (αA/αB(-/-)) develop cataracts. We used proteomic analysis to identify lens proteins that change in abundance after deletion of these α-crystallin genes. Wild-type (WT) and αA/αB(-/-) knockout (DKO) mice were compared using two-dimensional difference gel electrophoresis and mass spectrometric analysis, and protein identifications were validated by Mascot proteomic software. The abundance of histones H2A, H4, and H2B fragment, and a low molecular weight β1-catenin increased 2-3-fold in postnatal day 2 lenses of DKO lenses compared with WT lenses. Additional major increases were observed in abundance of βB2-crystallin and vimentin in 30-day-old lenses of DKO animals compared with WT animals. Lenses of DKO mice were comprised of nine protein spots containing βB2-crystallin at 10-40-fold higher abundance and three protein spots containing vimentin at ≥2-fold higher abundance than in WT lenses. Gel permeation chromatography identified a unique 328 kDa protein in DKO lenses, containing β-crystallin, demonstrating aggregation of β-crystallin in the absence of α-crystallins. Together, these changes provide biochemical evidence for possible functions of specific cell adhesion proteins, cytoskeletal proteins, and crystallins in lens opacities caused by the absence of the major chaperones, αA- and αB-crystallins.

Publication types

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

MeSH terms

  • Age Factors
  • Animals
  • Blotting, Western
  • Chromatography, Gel
  • Chromatography, High Pressure Liquid
  • Crystallins / genetics*
  • Crystallins / metabolism
  • Electrophoresis, Gel, Two-Dimensional
  • Heat-Shock Proteins / genetics*
  • Heat-Shock Proteins / metabolism
  • Histones / metabolism
  • Mass Spectrometry
  • Mice
  • Mice, Knockout
  • Proteomics*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Vimentin / metabolism
  • beta Catenin / genetics*
  • beta Catenin / metabolism

Substances

  • Crystallins
  • Heat-Shock Proteins
  • Histones
  • Vimentin
  • beta Catenin