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.
A Series of Molecular Signals That Proceeds with an Activated Receptor Promoting the Exchange of GDP For GTP On the Alpha Subunit of an Associated Heterotrimeric G Protein Complex. the GTP Bound Activated Alpha G Protein Then Dissociates From the Beta and Gamma Subunits to Further Transmit the Signal Within the Cell. the Pathway Begins with Receptor Ligand Interaction or For Basal Gpcr Signaling the Pathway Begins with the Receptor Activating Its G Protein in the Absence of an Agonist and Ends with Regulation of a Downstream Cellular Process E.g. Transcription.
The Chemical Reactions and Pathways Including Anabolism and Catabolism by Which Living Organisms Transform Chemical Substances. Metabolic Processes Typically Transform Small Molecules But Also Include Macromolecular Processes Such As DNA Repair and Replication and Protein Synthesis and Degradation.
Interacting Selectively and Non Covalently with a Nucleotide Any Compound Consisting of a Nucleoside That Is Esterified with (ortho)phosphate or an Oligophosphate At Any Hydroxyl Group On the Ribose or Deoxyribose.