Guanine nucleotide-binding protein subunit alpha-12 is a protein that in humans is encoded by the GNA12 gene. [5] [6] [7]
Guanine nucleotide-binding protein subunit alpha-12 is a protein that in humans is encoded by the GNA12 gene. [5] [6] [7]
The GNA12 gene encodes the G12 G protein alpha subunit. Together with GNA13, these two proteins comprise one of the four classes of heterotrimeric G protein alpha subunits. [8] Heterotrimeric G proteins function in transducing hormone and neurotransmitter signals detected by cell surface G protein-coupled receptors to intracellular signaling pathways to modulate cell functions. G protein alpha subunits bind to guanine nucleotides and function in a regulatory cycle, and are active when bound to GTP but inactive and associated with the G beta-gamma complex when bound to GDP. [9] [10]
Active GTP-bound G12 alpha subunit interacts with and activates ARHGEF1, [11] ARHGEF11, [12] [13] and ARHGEF12. [14] [15] These ARHGEF proteins function as guanine nucleotide exchange factors for the Rho small GTPases to regulate the actin cytoskeleton. [16]
GNA12 also interacts with PPP5C, [17] HSP90, [18] Resistance to inhibitors of cholinesterase-8A (Ric-8A) [19] and TEC. [15]
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. Their activity is regulated by factors that control their ability to bind to and hydrolyze guanosine triphosphate (GTP) to guanosine diphosphate (GDP). When they are bound to GTP, they are 'on', and, when they are bound to GDP, they are 'off'. G proteins belong to the larger group of enzymes called GTPases.
Heterotrimeric G protein, also sometimes referred to as the "large" G proteins are membrane-associated G proteins that form a heterotrimeric complex. The biggest non-structural difference between heterotrimeric and monomeric G protein is that heterotrimeric proteins bind to their cell-surface receptors, called G protein-coupled receptors, directly. These G proteins are made up of alpha (α), beta (β) and gamma (γ) subunits. The alpha subunit is attached to either a GTP or GDP, which serves as an on-off switch for the activation of G-protein.
The Gs alpha subunit is a subunit of the heterotrimeric G protein Gs that stimulates the cAMP-dependent pathway by activating adenylyl cyclase. Gsα is a GTPase that functions as a cellular signaling protein. Gsα is the founding member of one of the four families of heterotrimeric G proteins, defined by the alpha subunits they contain: the Gαs family, Gαi/Gαo family, Gαq family, and Gα12/Gα13 family. The Gs-family has only two members: the other member is Golf, named for its predominant expression in the olfactory system. In humans, Gsα is encoded by the GNAS complex locus, while Golfα is encoded by the GNAL gene.
G12/G13 alpha subunits are alpha subunits of heterotrimeric G proteins that link cell surface G protein-coupled receptors primarily to guanine nucleotide exchange factors for the Rho small GTPases to regulate the actin cytoskeleton. Together, these two proteins comprise one of the four classes of G protein alpha subunits. G protein alpha subunits bind to guanine nucleotides and function in a regulatory cycle, and are active when bound to GTP but inactive and associated with the G beta-gamma complex when bound to GDP. G12/G13 are not targets of pertussis toxin or cholera toxin, as are other classes of G protein alpha subunits.
Guanine nucleotide-binding protein G(q) subunit alpha is a protein that in humans is encoded by the GNAQ gene. Together with GNA11, it functions as a Gq alpha subunit.
Guanine nucleotide-binding protein G(i), alpha-2 subunit is a protein that in humans is encoded by the GNAI2 gene.
Guanine nucleotide-binding protein G(i), alpha-1 subunit is a protein that in humans is encoded by the GNAI1 gene.
Guanine nucleotide-binding protein G(o) subunit alpha is a protein that in humans is encoded by the GNAO1 gene.
A-kinase anchor protein 13 is a protein that in humans, is encoded by the AKAP13 gene. This protein is also called AKAP-Lbc because it encodes the lymphocyte blast crisis (Lbc) oncogene, and ARHGEF13/RhoGEF13 because it contains a guanine nucleotide exchange factor (GEF) domain for the RhoA small GTP-binding protein.
Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2 is a protein that in humans is encoded by the GNG2 gene.
Rho guanine nucleotide exchange factor 1 is a protein that in humans is encoded by the ARHGEF1 gene. This protein is also called RhoGEF1 or p115-RhoGEF.
Rho guanine nucleotide exchange factor 11 is a protein that in humans is encoded by the ARHGEF11 gene. This protein is also called RhoGEF11 or PDZ-RhoGEF.
Rho guanine nucleotide exchange factor 12 is a protein that in humans is encoded by the ARHGEF12 gene. This protein is also called RhoGEF12 or Leukemia-associated Rho guanine nucleotide exchange factor (LARG).
Guanine nucleotide-binding protein subunit beta-4 is a protein that in humans is encoded by the GNB4 gene.
Guanine nucleotide-binding protein G(olf) subunit alpha is a protein that in humans is encoded by the GNAL gene. Its main product is the heterotrimeric G-protein alpha subunit Golf-α, a member of the Gs alpha subunit family that is a key component of G protein-coupled receptor-regulated adenylyl cyclase signal transduction pathways in the olfactory system and the striatum in the brain. It also mediated D1 receptor signalling in the striatum and is hence involved in motor control.
Guanine nucleotide-binding protein subunit alpha-13 is a protein that in humans is encoded by the GNA13 gene.
Guanine nucleotide-binding protein G(k) subunit alpha is a protein that in humans is encoded by the GNAI3 gene.
Guanine nucleotide-binding protein subunit alpha-11 is a protein that in humans is encoded by the GNA11 gene. Together with GNAQ, it functions as a Gq alpha subunit.
GoLoco motif is a protein structural motif. In heterotrimeric G-protein signalling, cell surface receptors (GPCRs) are coupled to membrane-associated heterotrimers comprising a GTP-hydrolyzing subunit G-alpha and a G-beta/G-gamma dimer. The inactive form contains the alpha subunit bound to GDP and complexes with the beta and gamma subunit. When the ligand is associated to the receptor, GDP is displaced from G-alpha and GTP is bound. The GTP/G-alpha complex dissociates from the trimer and associates to an effector until the intrinsic GTPase activity of G-alpha returns the protein to GDP bound form. Reassociation of GDP-bound G-alpha with G-beta/G-gamma dimer terminates the signal. Several mechanisms regulate the signal output at different stage of the G-protein cascade. Two classes of intracellular proteins act as inhibitors of G protein activation: GTPase activating proteins (GAPs), which enhance GTP hydrolysis, and guanine dissociation inhibitors (GDIs), which inhibit GDP dissociation. The GoLoco or G-protein regulatory (GPR) motif found in various G-protein regulators. acts as a GDI on G-alpha(i).
Pleckstrin homology domain containing, family G member 2 (PLEKHG2) is a protein that in humans is encoded by the PLEKHG2 gene. It is sometimes written as ARHGEF42, FLJ00018.
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