Descriptions

Gαi1 is a G-protein alpha subunit that plays a crucial role in signal transduction pathway initiated by G-protein-coupled receptor (GPCR) activation. G proteins function as transducers downstream of GPCRs in numerous signaling cascades. The alpha subunit contains the guanine nucleotide binding site and alternates between an active (GTP-bound state) and an inactive (GDP-bound state). Activated GPCR induces conformational change in Gαi1, which allows for GDP-to-GTP exchange by binding to the GPCR-binding site within a Ras-like domain, leading to dissociation of the Gαi1 subunit and initiation of downstream signaling.

Autoinhibitory domains (AIDs)

Target domain

185-348 (Ras-like domain)

Relief mechanism

Ligand binding, Partner binding

Assay

Accessory elements

No accessory elements

Autoinhibited structure

Activated structure

2 structures for P18872

Entry ID Method Resolution Chain Position Source
3C7K X-ray 290 A A/C 22-354 PDB
AF-P18872-F1 Predicted AlphaFoldDB

11 variants for P18872

Variant ID(s) Position Change Description Diseaes Association Provenance
rs3388997597 89 D>E No EVA
rs3388987944 98 K>* No EVA
rs3388997547 108 C>* No EVA
rs3389002324 127 A>T No EVA
rs3388970196 154 K>E No EVA
rs3388981626 277 E>D No EVA
rs3388970178 279 I>N No EVA
rs3388987947 284 L>M No EVA
rs3388998712 285 T>I No EVA
rs3388987945 327 T>I No EVA
rs3389001680 333 Q>* No EVA

No associated diseases with P18872

2 regional properties for P18872

Type Name Position InterPro Accession
domain Nuclear hormone receptor, ligand-binding domain 177 - 403 IPR000536
domain Zinc finger, nuclear hormone receptor-type 76 - 151 IPR001628

Functions

Description
EC Number
Subcellular Localization
  • Cell membrane
  • Membrane ; Lipid-anchor
PANTHER Family
PANTHER Subfamily
PANTHER Protein Class
PANTHER Pathway Category No pathway information available

7 GO annotations of cellular component

Name Definition
cell body The portion of a cell bearing surface projections such as axons, dendrites, cilia, or flagella that includes the nucleus, but excludes all cell projections.
cytoplasm The contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.
dendrite A neuron projection that has a short, tapering, morphology. Dendrites receive and integrate signals from other neurons or from sensory stimuli, and conduct nerve impulses towards the axon or the cell body. In most neurons, the impulse is conveyed from dendrites to axon via the cell body, but in some types of unipolar neuron, the impulse does not travel via the cell body.
heterotrimeric G-protein complex Any of a family of heterotrimeric GTP-binding and hydrolyzing proteins; they belong to a superfamily of GTPases that includes monomeric proteins such as EF-Tu and RAS. Heterotrimeric G-proteins consist of three subunits; the alpha subunit contains the guanine nucleotide binding site and possesses GTPase activity; the beta and gamma subunits are tightly associated and function as a beta-gamma heterodimer; extrinsic plasma membrane proteins (cytoplasmic face) that function as a complex to transduce signals from G protein-coupled receptors to an effector protein.
membrane A lipid bilayer along with all the proteins and protein complexes embedded in it and attached to it.
myelin sheath An electrically insulating fatty layer that surrounds the axons of many neurons. It is an outgrowth of glial cells
plasma membrane The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins.

9 GO annotations of molecular function

Name Definition
corticotropin-releasing hormone receptor 1 binding Binding to a corticotropin-releasing hormone receptor 1 (CRHR1). CRHR1 is the major subtype in the pituitary corticotroph, and mediates the stimulatory actions of corticotropin-releasing hormone on corticotropin hormone secretion. CRHR1 are also located in cortical areas of the brain, cerebellum and limbic system.
G protein-coupled serotonin receptor binding Binding to a metabotropic serotonin receptor.
G-protein beta/gamma-subunit complex binding Binding to a complex of G-protein beta/gamma subunits.
GTP binding Binding to GTP, guanosine triphosphate.
GTPase activating protein binding Binding to a GTPase activating protein.
GTPase activity Catalysis of the reaction
metal ion binding Binding to a metal ion.
mu-type opioid receptor binding Binding to a mu-type opioid receptor.
signaling receptor binding Binding to one or more specific sites on a receptor molecule, a macromolecule that undergoes combination with a hormone, neurotransmitter, drug or intracellular messenger to initiate a change in cell function.

9 GO annotations of biological process

Name Definition
adenylate cyclase-modulating G protein-coupled receptor signaling pathway A G protein-coupled receptor signaling pathway in which the signal is transmitted via the activation or inhibition of adenylyl cyclase activity and a subsequent change in the intracellular concentration of cyclic AMP (cAMP).
dopamine receptor signaling pathway The series of molecular signals generated as a consequence of a dopamine receptor binding to one of its physiological ligands.
G protein-coupled receptor signaling pathway The series of molecular signals initiated by a ligand binding to its receptor, in which the activated receptor promotes 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, and ends with regulation of a downstream cellular process. The pathway can start from the plasma membrane, Golgi or nuclear membrane.
locomotory behavior The specific movement from place to place of an organism in response to external or internal stimuli. Locomotion of a whole organism in a manner dependent upon some combination of that organism's internal state and external conditions.
negative regulation of calcium ion transport Any process that stops, prevents, or reduces the frequency, rate or extent of the directed movement of calcium ions into, out of or within a cell, or between cells, by means of some agent such as a transporter or pore.
negative regulation of insulin secretion Any process that stops, prevents, or reduces the frequency, rate or extent of the regulated release of insulin.
regulation of heart contraction Any process that modulates the frequency, rate or extent of heart contraction. Heart contraction is the process in which the heart decreases in volume in a characteristic way to propel blood through the body.
response to organonitrogen compound Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of an organonitrogen stimulus. An organonitrogen compound is formally a compound containing at least one carbon-nitrogen bond.
vesicle docking involved in exocytosis The initial attachment of a vesicle membrane to a target membrane, mediated by proteins protruding from the membrane of the vesicle and the target membrane, that contributes to exocytosis.

58 homologous proteins in AiPD

UniProt AC Gene Name Protein Name Species Evidence Code
P63097 GNAI1 Guanine nucleotide-binding protein G Bos taurus (Bovine) SS
P0C7Q4 GNAT3 Guanine nucleotide-binding protein G Bos taurus (Bovine) SS
P04696 GNAT2 Guanine nucleotide-binding protein G Bos taurus (Bovine) SS
P04695 GNAT1 Guanine nucleotide-binding protein G Bos taurus (Bovine) SS
P08239 GNAO1 Guanine nucleotide-binding protein G Bos taurus (Bovine) SS
P50147 GNAI2 Guanine nucleotide-binding protein G Gallus gallus (Chicken) SS
P50146 GNAI1 Guanine nucleotide-binding protein G Gallus gallus (Chicken) SS
P20353 Galphai G protein alpha i subunit Drosophila melanogaster (Fruit fly) SS
P25157 cta Guanine nucleotide-binding protein subunit alpha homolog Drosophila melanogaster (Fruit fly) SS
P16378 Galphao G protein alpha o subunit Drosophila melanogaster (Fruit fly) SS
P11488 GNAT1 Guanine nucleotide-binding protein G Homo sapiens (Human) SS
P19087 GNAT2 Guanine nucleotide-binding protein G Homo sapiens (Human) SS
Q03113 GNA12 Guanine nucleotide-binding protein subunit alpha-12 Homo sapiens (Human) SS
P04899 GNAI2 Guanine nucleotide-binding protein G Homo sapiens (Human) SS
P63096 GNAI1 Guanine nucleotide-binding protein G Homo sapiens (Human) EV
P08754 GNAI3 Guanine nucleotide-binding protein G Homo sapiens (Human) SS
A8MTJ3 GNAT3 Guanine nucleotide-binding protein G Homo sapiens (Human) SS
Q14344 GNA13 Guanine nucleotide-binding protein subunit alpha-13 Homo sapiens (Human) SS
P19086 GNAZ Guanine nucleotide-binding protein G Homo sapiens (Human) SS
P09471 GNAO1 Guanine nucleotide-binding protein G Homo sapiens (Human) SS
P27601 Gna13 Guanine nucleotide-binding protein subunit alpha-13 Mus musculus (Mouse) SS
P27600 Gna12 Guanine nucleotide-binding protein subunit alpha-12 Mus musculus (Mouse) SS
P30678 Gna15 Guanine nucleotide-binding protein subunit alpha-15 Mus musculus (Mouse) PR
P21279 Gnaq Guanine nucleotide-binding protein G(q) subunit alpha Mus musculus (Mouse) PR
Q3V3I2 Gnat3 Guanine nucleotide-binding protein G Mus musculus (Mouse) SS
P50149 Gnat2 Guanine nucleotide-binding protein G Mus musculus (Mouse) SS
P20612 Gnat1 Guanine nucleotide-binding protein G Mus musculus (Mouse) SS
P08752 Gnai2 Guanine nucleotide-binding protein G Mus musculus (Mouse) SS
Q9DC51 Gnai3 Guanine nucleotide-binding protein G Mus musculus (Mouse) SS
O70443 Gnaz Guanine nucleotide-binding protein G Mus musculus (Mouse) SS
B2RSH2 Gnai1 Guanine nucleotide-binding protein G Mus musculus (Mouse) SS
P93564 GPA1 Guanine nucleotide-binding protein alpha-1 subunit Solanum tuberosum (Potato) SS
Q63210 Gna12 Guanine nucleotide-binding protein subunit alpha-12 Rattus norvegicus (Rat) SS
P19627 Gnaz Guanine nucleotide-binding protein G Rattus norvegicus (Rat) SS
P29348 Gnat3 Guanine nucleotide-binding protein G Rattus norvegicus (Rat) SS
P04897 Gnai2 Guanine nucleotide-binding protein G Rattus norvegicus (Rat) SS
P08753 Gnai3 Guanine nucleotide-binding protein G Rattus norvegicus (Rat) SS
Q6Q7Y5 Gna13 Guanine nucleotide-binding protein subunit alpha-13 Rattus norvegicus (Rat) SS
P59215 Gnao1 Guanine nucleotide-binding protein G Rattus norvegicus (Rat) SS
Q0DJ33 GPA1 Guanine nucleotide-binding protein alpha-1 subunit Oryza sativa subsp. japonica (Rice) SS
O76584 gpa-11 Guanine nucleotide-binding protein alpha-11 subunit Caenorhabditis elegans SS
Q93743 gpa-6 Guanine nucleotide-binding protein alpha-6 subunit Caenorhabditis elegans SS
Q20907 gpa-8 Guanine nucleotide-binding protein alpha-8 subunit Caenorhabditis elegans PR
P91907 gpa-15 Guanine nucleotide-binding protein alpha-15 subunit Caenorhabditis elegans SS
Q21917 gpa-7 Guanine nucleotide-binding protein alpha-7 subunit Caenorhabditis elegans SS
Q9BIG5 gpa-4 Guanine nucleotide-binding protein alpha-4 subunit Caenorhabditis elegans SS
Q9N2V6 gpa-16 Guanine nucleotide-binding protein alpha-16 subunit Caenorhabditis elegans SS
Q9XTB2 gpa-13 Guanine nucleotide-binding protein alpha-13 subunit Caenorhabditis elegans SS
P28052 gpa-3 Guanine nucleotide-binding protein alpha-3 subunit Caenorhabditis elegans SS
P28051 gpa-1 Guanine nucleotide-binding protein alpha-1 subunit Caenorhabditis elegans SS
Q9BIG4 gpa-10 Guanine nucleotide-binding protein alpha-10 subunit Caenorhabditis elegans PR
Q18434 odr-3 Guanine nucleotide-binding protein alpha-17 subunit Caenorhabditis elegans SS
P51875 goa-1 Guanine nucleotide-binding protein G Caenorhabditis elegans SS
P93163 GPA2 Guanine nucleotide-binding protein alpha-2 subunit Glycine max (Soybean) (Glycine hispida) SS
P49084 GPA1 Guanine nucleotide-binding protein alpha-1 subunit Glycine max (Soybean) (Glycine hispida) SS
O80462 XLG1 Extra-large guanine nucleotide-binding protein 1 Arabidopsis thaliana (Mouse-ear cress) PR
P18064 GPA1 Guanine nucleotide-binding protein alpha-1 subunit Arabidopsis thaliana (Mouse-ear cress) SS
P26981 GPA1 Guanine nucleotide-binding protein alpha-1 subunit Solanum lycopersicum (Tomato) (Lycopersicon esculentum) SS
10 20 30 40 50 60
MGCTLSAEER AALERSKAIE KNLKEDGISA AKDVKLLLLG AGESGKSTIV KQMKIIHEDG
70 80 90 100 110 120
FSGEDVKQYK PVVYSNTIQS LAAIVRAMDT LGVEYGDKER KTDSKMVCDV VSRMEDTEPF
130 140 150 160 170 180
SAELLSAMMR LWGDSGIQEC FNRSREYQLN DSAKYYLDSL DRIGAGDYQP TEQDILRTRV
190 200 210 220 230 240
KTTGIVETHF TFKNLHFRLF DVGGQRSERK KWIHCFEDVT AIIFCVALSG YDQVLHEDET
250 260 270 280 290 300
TNRMHESLML FDSICNNKFF IDTSIILFLN KKDLFGEKIK KSPLTICFPE YPGSNTYEDA
310 320 330 340 350
AAYIQTQFES KNRSPNKEIY CHMTCATDTN NIQVVFDAVT DIIIANNLRG CGLY