PURPOSE: The aim of this study was to elucidate the molecular mechanisms that lead to a dominant nuclear cataract in a mouse harboring the Y118D mutation in the alphaA-crystallin gene. METHODS: The physicochemical properties of alpha-crystallin obtained from mouse lenses with the Y118D mutation as well as a recombinant Y118D alphaA-crystallin were studied using gel filtration, two-dimensional (2D) gel electrophoresis, multi-angle light scattering, circular dichroism, fluorescence, and chaperone activities. RESULTS: Both native alpha-crystallin from mutant lens and recombinant alphaA-Y118D displayed higher molecular mass distribution than the wild-type. Circular dichroism spectra indicated changes in the secondary structures of alphaA-Y118D. The alphaA-Y118D protein prevented nonspecific protein aggregation more effectively than wild-type alphaA-crystallin. The gel filtration and 2D gel electrophoresis analysis showed a significant reduction of Y118D mutant protein in comparison with wild-type alphaA protein of heterozygous mutant lenses. Quantitative RT-PCR results confirmed a decrease in alphaA and alphaB transcripts in the homozygous mutant alpha A(Y118D/Y118D) lenses. CONCLUSIONS: The alphaA-Y118D mutant protein itself displays an increased chaperone-like activity. However, the dominant nuclear cataract is associated with a significant decrease in the amount of alphaA-crystallin, leading to a reduction in total chaperone capacity needed for maintaining lens transparency.
PURPOSE: The aim of this study was to elucidate the molecular mechanisms that lead to a dominant nuclear cataract in a mouse harboring the Y118D mutation in the alphaA-crystallin gene. METHODS: The physicochemical properties of alpha-crystallin obtained from mouse lenses with the Y118D mutation as well as a recombinant Y118DalphaA-crystallin were studied using gel filtration, two-dimensional (2D) gel electrophoresis, multi-angle light scattering, circular dichroism, fluorescence, and chaperone activities. RESULTS: Both native alpha-crystallin from mutant lens and recombinant alphaA-Y118D displayed higher molecular mass distribution than the wild-type. Circular dichroism spectra indicated changes in the secondary structures of alphaA-Y118D. The alphaA-Y118D protein prevented nonspecific protein aggregation more effectively than wild-type alphaA-crystallin. The gel filtration and 2D gel electrophoresis analysis showed a significant reduction of Y118D mutant protein in comparison with wild-type alphaA protein of heterozygous mutant lenses. Quantitative RT-PCR results confirmed a decrease in alphaA and alphaB transcripts in the homozygous mutant alpha A(Y118D/Y118D) lenses. CONCLUSIONS: The alphaA-Y118D mutant protein itself displays an increased chaperone-like activity. However, the dominant nuclear cataract is associated with a significant decrease in the amount of alphaA-crystallin, leading to a reduction in total chaperone capacity needed for maintaining lens transparency.
Authors: J Graw; J Löster; D Soewarto; H Fuchs; B Meyer; A Reis; E Wolf; R Balling; M Hrabé de Angelis Journal: Invest Ophthalmol Vis Sci Date: 2001-11 Impact factor: 4.799
Authors: Mohammad S Z Ahmad; Mahmoud Ahmed; Milad Khedr; Alfredo Borgia; Andrea Madden; Lakshminarayan R Ranganath; Stephen Kaye Journal: JIMD Rep Date: 2022-04-09
Authors: Jonathan A Wignes; Joshua W Goldman; Conrad C Weihl; Matthew G Bartley; Usha P Andley Journal: Exp Eye Res Date: 2013-07-18 Impact factor: 3.467