Arginine 54 and Tyrosine 118 Residues of αA-Crystallin Are Crucial for Lens Formation and Transparency
| Autor: | Debra Cheung, Bo Chang, Haiquan Liu, Min Wang, Catherine Cheng, Qingling Huang, Joseph Horwitz, Xiaohua Gong, Chun-hong Xia |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Male
Genetic Linkage Green Fluorescent Proteins Mutant Genes Recessive Gene mutation Biology Arginine medicine.disease_cause alpha-Crystallin A Chain Cataract Green fluorescent protein Mice Crystallin Lens Crystalline medicine Animals Point Mutation Electrophoresis Gel Two-Dimensional Gene Actin Genes Dominant Mice Inbred C3H Mutation Point mutation Chromosome Mapping Epithelial Cells Molecular biology Actins eye diseases Mitochondria Mice Inbred C57BL Disease Models Animal Phenotype Tyrosine Female sense organs |
| Zdroj: | Investigative Opthalmology & Visual Science. 47:3004 |
| ISSN: | 1552-5783 |
| DOI: | 10.1167/iovs.06-0178 |
| Popis: | Purpose To identify new mouse models for studying roles of alphaAlpha-crystallin in vivo and to investigate why and how different mutations of the alphaAlpha-crystallin gene lead to dominant or recessive cataracts. Methods Using mouse genetic approaches and slit lamp screening, we identified two mouse cataractous mutant lines. Causative genes were mapped by a genome-wide linkage analysis. DNA sequencing verified missense mutations of alphaA-crystallin gene in both mutant lines. Histology, imaging of green fluorescent protein (GFP)-positive lenses, and protein 2-DE gel were used to determine the morphologic and biochemical properties of mutant lenses. Results Two new alphaA-crystallin gene mutations were identified, alphaA-R54C (alphaA-Cys) and alphaA-Y118D, which cause recessive whole cataracts and dominant nuclear cataracts, respectively. In homozygous alphaA-Cys mutant mice, lens epithelial and fiber cells lost their characteristic cellular features and developed disrupted subcellular structures, such as actin filaments and mitochondria. The nuclear cataract caused by alphaA-Y118D mutation was associated with increased water-insoluble crystallins (alpha, beta, and gamma classes). These results suggest that the Arg54 residue in the N-terminal region is crucial for alphaA-crystallin to perform its roles in lens epithelial and fiber cells during development, whereas the Y118D mutation in the central alpha-crystallin domain impairs alphaA-crystallin's ability to maintain the solubility of crystallin proteins in the lens. Conclusions This work demonstrates that different regions of alphaA-crystallin mediate distinct functions in vivo. These two mutant mouse lines provide useful animal models for further investigating the multiple roles of alphaA-crystallin in the lens. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|