Tacks a phosphate group onto the switch protein
Plucks a phosphate off a switch protein
Nitric Oxide (NO)
This gas diffuses readily out of the cell that generates it and enters neighboring cells.
Receipt of a signal causes them to toggle from an inactive to an active state. Once activated, these proteins can turn on other proteins in the signaling pathway.
Phosphorylate proteins on serines or threonines
Phosphorylate proteins on tyrosines
These switch between an active and an inactive state depending on whether they have GTP or GDP bound to them, respectively.
These receptors are responsible for the rapid transmission of signals across synapses in the nervous system.
G-Protein-Coupled Receptors (GPCRs)
These receptors mediate responses to an enormous diversity of extracellular signal molecules, including hormones, local mediators, and neurotransmitters. Each is made of a single polypeptide chain that threads back and forth across the lipid bi-layer seven times.
One of the largest family of GTP-binding proteins composed of three different subunits that are important intermediates intracellular signalling pathways. Usually activated by the binding of a hormone or other ligand to a transmembrane receptor.
Small molecule formed in or released into the cytosol in response to an extracellular signal that helps to relay the signal to the interior of the cell. Examples include cAMP, IP3, and Ca2+
Enzyme that catalyzes the formation of cyclic AMP from ATP. An important component of some intracellular signaling pathways.
Nucleotide generated from ATP in response to hormonal stimulation of cell-surface receptors. Acts as a signaling molecule by activating protein kinase A; it is hydrolyzed to AMP by a phosphodiesterase.