Signal transduction by MAP kinases: regulation by phosphorylation-dependent switches.
The kinases of mitogen-activated protein (MAP) kinase cascades transmit signals through sequential phosphorylation and activation of the enzymes. However, recent evidence indicates that protein-protein interactions between the kinases themselves or with substrates or other components are also a critical means of regulation. Whitmarsh and Davis summarize these findings with emphasis on new evidence from yeast that, when phosphorylated, a MAP kinase kinase actually switches from a negative regulator that binds to and inhibits its target MAP kinase to a positive regulator of that same enzyme.
Whitmarsh
A J
AJ
Howard Hughes Medical Institute, Program in Molecular Medicine, Department of Biochemistry, University of Massachusetts Medical School, Worcester, MA 01605 USA. roger.davis@umassmed.edu
Davis
R J
RJ
D000818:Animals; D006801:Humans; D020935:MAP Kinase Signaling System / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism / Q000502:physiology*; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
D010770:Phosphotransferases; D020928:Mitogen-Activated Protein Kinases