文摘
Mice with deletion of genes for small heat shock proteins 伪A- and 伪B-crystallin (伪A/伪B鈥?鈥?/sup>) develop cataracts. We used proteomic analysis to identify lens proteins that change in abundance after deletion of these 伪-crystallin genes. Wild-type (WT) and 伪A/伪B鈥?鈥?/sup> 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 尾1-catenin increased 2鈥?-fold in postnatal day 2 lenses of DKO lenses compared with WT lenses. Additional major increases were observed in abundance of 尾B2-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 尾B2-crystallin at 10鈥?0-fold higher abundance and three protein spots containing vimentin at 鈮?-fold higher abundance than in WT lenses. Gel permeation chromatography identified a unique 328 kDa protein in DKO lenses, containing 尾-crystallin, demonstrating aggregation of 尾-crystallin in the absence of 伪-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, 伪A- and 伪B-crystallins.