View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Leading Edge Essay Phosphotyrosine Signaling: Evolving a New Cellular Communication System Wendell A. Lim1,2,* and Tony Pawson3,4,* 1Howard Hughes Medical Institute 2Department of Cellular and Molecular Pharmacology University of California, San Francisco, San Francisco, CA 94158, USA 3Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada 4Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada *Correspondence:
[email protected] (W.A.L.),
[email protected] (T.P.) DOI 10.1016/j.cell.2010.08.023 Tyrosine phosphorylation controls many cellular functions. Yet the three-part toolkit that regulates phosphotyrosine signaling—tyrosine kinases, phosphotyrosine phosphatases, and Src Homology 2 (SH2) domains—is a relatively new innovation. Genomic analyses reveal how this revolutionary signaling system may have originated and why it rapidly became critical to metazoans. Throughout human history, new technolo- (TyrK) phosphorylate specific target with an evolutionary process? Proteins gies and technological platforms have tyrosine residues, phosphotyrosine phos- that bind or remove a posttranslational constantly been invented. Only a small phatases (PTP) remove the phosphates, modification would seem useless without fraction of these technologies go on to and Src Homology 2 (SH2) domains an enzyme to generate the modification be widely adopted, but these can recognize the modifications (Pawson and, in principle, would not provide ultimately have transformational conse- 1995). Together, these three modules a fitness advantage leading to its retention quences. In the evolutionary history of form the ‘‘writer,’’ ‘‘eraser,’’ and ‘‘reader’’ and spread.