The Cellular Process in Which a Signal Is Conveyed to Trigger a Change in the Activity or State of a Cell. Signal Transduction Begins with Reception of a Signal (e.g. a Ligand Binding to a Receptor or Receptor Activation by a Stimulus Such As Light) or For Signal Transduction in the Absence of Ligand Signal Withdrawal or the Activity of a Constitutively Active Receptor. Signal Transduction Ends with Regulation of a Downstream Cellular Process E.g. Regulation of Transcription or Regulation of a Metabolic Process. Signal Transduction Covers Signaling From Receptors Located On the Surface of the Cell and Signaling Via Molecules Located Within the Cell. For Signaling Between Cells Signal Transduction Is Restricted to Events At and Within the Receiving Cell.
Transmembrane Receptor Protein Tyrosine Kinase Activity
Combining with a Signal and Transmitting the Signal From One Side of the Membrane to the Other to Initiate a Change in Cell Activity by Catalysis of the Reaction: ATP + a Protein L Tyrosine = Adp + a Protein L Tyrosine Phosphate.