Dual specificity kinases that phosphorylate the Thr- and Tyr-residues within the TXY motif of MAP-kinases of play a central role in the regulation of various processes of cell growth. These dual specificity kinases also known as MAP kinase kinases are constituents of the sequential kinase signaling modules. Seven distinct mammalian MAP kinases kinases have been identified. Some of the unique signaling properties of these kinases are discussed here.
Fels Institute for Cancer Research and Molecular Biology and Department of Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.
