The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 

Phosphatidylinositol 3-kinase in bovine lens and its stimulation by insulin and IGF-1.

PURPOSE: To identify and characterize phosphatidylinositol 3-kinase ( PI-3K) in the lens and to study its involvement as a signal mediator in lens epithelial cells exposed to insulin and insulin-like growth factor (IGF)-1, which are known to induce lens epithelial cell proliferation and differentiation into fiber cells. METHODS: Concentric fiber cell layers from single bovine lens were prepared by dissolution in buffer. PI-3K activity in capsule-epithelium and fiber cell layers was determined after immunoprecipitation with antibodies against p85, the regulatory subunit of PI-3K. High-performance liquid chromatography on an ion exchange column (Partisil-SAX; Whatman, Maidstone, United Kingdom) was used to identify PI-3K reaction products. Cultured bovine lens epithelial cells were stimulated with insulin or IGF-1, and PI-3K activity was determined after immunoprecipitation with antibody against phosphotyrosine. Association of p85 with other proteins after stimulation was determined in anti-p85 immunoprecipitates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western immunoblot analysis using anti-phosphotyrosine antibody. RESULTS: PI-3K activity was found in both lens epithelial cells and fiber cells. The highest specific activity was found in the capsule-epithelium, but there was considerable activity in other fiber cell layers. Insulin and IGF-1 stimulated the PI-3K activity in epithelial cells in culture by more than 100%, and activation of the enzyme resulted in tyrosine phosphorylation of the p85 subunit. After stimulation, the p85 subunit of PI-3K was associated with 100- and 180-kDa tyrosine phosphorylated proteins. CONCLUSIONS: The activation of PI-3K and its association with specific tyrosine- phosphorylated proteins may be important in insulin and IGF-1 signal transduction in lens epithelial cells. The presence of significant PI-3K activity throughout the lens further suggests that this signal transduction enzyme is sustained in fiber cells.[1]

References

  1. Phosphatidylinositol 3-kinase in bovine lens and its stimulation by insulin and IGF-1. Chandrasekher, G., Bazan, H.E. Invest. Ophthalmol. Vis. Sci. (2000) [Pubmed]
 
WikiGenes - Universities