Signal Transduction (IND 447)

Tyrosine Phosphorylation

Robert Mooney, Ph.D. 

Cells of eukaryotic organisms coordinate their functions through environmental signals - growth factors (cytokines), extracellular matrix, neighboring cells. Transmembrane receptors receive these extracellular cues and transduce signals into the cell for appropriate response. One major mechanism by which transmembrane receptors signal is through tyrosine kinase pathways. Though tyrosine phosphorylation events are rare relative to serine/threonine phosphorylation, tyrosine kinase pathways are critical for cell growth, differentiation and metabolic regulation. The phosphorylation state of any cellular target protein is the net effect of tyrosine kinase (TK) activity and corresponding protein tyrosine phosphatase (PTPs) activity. Cells contain a diverse array of both enzyme families.

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