THE INS AND OUTS OF RAF KINASES

Raf kinases are signal-integrating enzymes that have the ability to sw itch tyrosine kinase signalling to serine/threonine phosphorylation an d connect growth factor receptors with transcription factors. The conn ection involves a cascade of protein kinases that is essential for cel lular proliferation and differentiation of species ranging from worms to humans. This cascade also mediates transformation by most oncogenes .