Search results
Results from the WOW.Com Content Network
Phosducin-transducin beta-gamma complex. Beta and gamma subunits of G-protein are shown by blue and red, respectively. Guanosine diphosphate Guanosine triphosphate. G proteins, also known as guanine nucleotide-binding proteins, are a family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to its interior.
For example, in adipose tissues, two different G-proteins with interchangeable beta-gamma complexes are used to activate or inhibit adenylyl cyclase. The alpha subunit of a stimulatory G protein activated by receptors for stimulatory hormones could stimulate adenylyl cyclase, which activates cAMP used for downstream signal cascades.
For example, binding of G proteins to receptors affects the receptor's affinity for ligands. Activated G proteins are bound to GTP. Further signal transduction depends on the type of G protein. The enzyme adenylate cyclase is an example of a cellular protein that can be regulated by a G protein, in this case the G protein G s. Adenylate cyclase ...
The large G proteins, for example, are involved in transduction of signaling from the G protein-coupled receptor for a variety of signaling processes like hormonal signaling, [2] and small G proteins are involved in processes like cellular trafficking and cell cycling. [3] GAP's role in this function is to turn the G protein's activity off.
Small GTPases (EC 3.6.5.2), also known as small G-proteins, are a family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate (GTP). They are a type of G-protein found in the cytosol that are homologous to the alpha subunit of heterotrimeric G-proteins, but unlike the alpha subunit of G proteins, a small GTPase can function independently as a hydrolase enzyme to bind to and ...
The G protein-coupled inwardly rectifying potassium channels (GIRKs) are a family of lipid-gated inward-rectifier potassium ion channels which are activated (opened) by the signaling lipid PIP2 and a signal transduction cascade starting with ligand-stimulated G protein-coupled receptors (GPCRs).
The G s alpha subunit slowly catalyzes the hydrolysis of GTP to GDP, which in turn deactivates the G s protein, shutting off the cAMP pathway. The pathway may also be deactivated downstream by directly inhibiting adenylyl cyclase or dephosphorylating the proteins phosphorylated by PKA. Molecules that inhibit the cAMP pathway include:
The Rho family of GTPases is a family of small (~21 kDa) signaling G proteins, and is a subfamily of the Ras superfamily.The members of the Rho GTPase family have been shown to regulate many aspects of intracellular actin dynamics, and are found in all eukaryotic kingdoms, including yeasts and some plants.