ABSTRACT
Phosphorylation of proteins on their threonine, serine, and tyrosine residues is one of the most commonly occurring posttranslational modifications in eukaryotic cells. Cellular phosphorylation cascades facilitates the amplification of extracellular signals following changes in environmental conditions via the ability of phosphorylated activators to modulate the expression of numerous genes. Because these reactions are rapidly reversible, they are important for the regulation of many cellular functions including signal transduction, cell division, and proliferation. Hyperosmolality can induce tyrosine phosphorylation of TonEBP/OREBP. Tyrosine phosphorylation by Abl kinases of several target proteins is a key mechanism for modulating signal transduction in hyperosmolar conditions. In this review article we discuss the role of Abl tyrosine kinases and DNA methylation during glucose induced hyperosmolality.