Abstract
Abstract: :
Purpose: The sphingomyelin pathway, in addition to the importance of sphingolipids in membrane structure, with its lipid products ceramide, sphingosine, and phosphorylated derivatives exhibit an intriguing range of biological activities. Studies in mammalian systems implicate these lipids in signaling processes involving both activation of cell growth, death and differentiation. Sphingosine 1–phosphate is a bioactive lipid produced from the metabolism of sphingolipids that regulates vital biological processes, among which cell growth, survival, and motility are prominent. Sphingosine 1–phosphate is produced by sphingosine kinase (SPHK). The goal of the present study was to determine the cellular localization of sphingosine kinase in bovine lens. Methods: Bovine lenses were divided into subcellular fractions. Protein concentrations were determined for each fraction and 100 micrograms from each sample was applied Western blotting. SPHK was probed using two different polyclonal specific against different regions of sphingosine kinase 1. Results: Sphingosine kinase was found in urea soluble and insoluble fraction indicating its association with plasma membrane. In addition, SPHK was also detected in the urea insoluble fraction of cortex and nuclear fraction of bovine lens. The highest level of SPHK protein was detected in the urea insoluble fraction. Conclusions: The bovine lens contains SPHK, is primarily associated with lens plasma membrane. Since SPHK is present in higher concentration in the urea soluble and insoluble fraction, it signifies its biological role in sphingolipid modulation and cellular signaling
Keywords: enzymes/enzyme inhibitors • cell membrane/membrane specializations