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guanyl-nucleotide exchange factor complex

Definition

Target type: cellularcomponent

A protein complex that stimulates the exchange of guanyl nucleotides associated with a GTPase. [GOC:mah]

The guanyl-nucleotide exchange factor (GEF) complex is a multi-protein assembly that plays a crucial role in regulating the activity of small GTPases, particularly members of the Ras superfamily. These GTPases act as molecular switches, cycling between an inactive GDP-bound state and an active GTP-bound state. GEFs catalyze the exchange of GDP for GTP, thereby activating the GTPases. The precise composition and organization of GEF complexes vary depending on the specific GTPase and cellular context. However, a common core component includes a GEF protein that directly interacts with the GTPase, often through a conserved domain called the Dbl homology (DH) domain. This interaction facilitates the release of GDP from the GTPase, allowing GTP to bind and activate it. In addition to the GEF protein, GEF complexes frequently incorporate regulatory subunits, such as scaffold proteins, which can provide spatial organization, target the complex to specific cellular locations, or modulate its activity. These regulatory subunits can also interact with other signaling molecules, integrating GEF activity into broader cellular signaling networks. The cellular component of a GEF complex is typically localized to specific membrane compartments, often in close proximity to the GTPase targets. This localization ensures efficient activation of the GTPase and facilitates downstream signaling events. For instance, GEFs for Ras GTPases are commonly found at the plasma membrane, where Ras activation triggers various signaling pathways involved in cell growth, differentiation, and survival. Similarly, GEFs for Rho GTPases are often localized to focal adhesions, where they control cytoskeletal rearrangements and cell motility. The cellular component of the GEF complex therefore plays a critical role in regulating GTPase activity and influencing a wide range of cellular processes.'
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Proteins (3)

ProteinDefinitionTaxonomy
Phosphodiesterase [no definition available]Bos taurus (cattle)
Ras guanyl-releasing protein 3A Ras guanyl-releasing protein 3 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q8IV61]Homo sapiens (human)
cGMP-inhibited 3',5'-cyclic phosphodiesterase BA cGMP-inhibited 3,5-cyclic phosphodiesterase 3B that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q13370]Homo sapiens (human)

Compounds (60)

CompoundDefinitionClassesRoles
my 5445MY 5445: potential platelet aggregation inhibitorpyridazines;
ring assembly
theophyllinedimethylxanthineadenosine receptor antagonist;
anti-asthmatic drug;
anti-inflammatory agent;
bronchodilator agent;
drug metabolite;
EC 3.1.4.* (phosphoric diester hydrolase) inhibitor;
fungal metabolite;
human blood serum metabolite;
immunomodulator;
muscle relaxant;
vasodilator agent
cilostamidecilostamide: selective inhibitor of cyclic AMP phosphodiesterase & platelet aggregation; structurequinolines
cilostazollactam;
tetrazoles
anticoagulant;
bronchodilator agent;
EC 3.1.4.17 (3',5'-cyclic-nucleotide phosphodiesterase) inhibitor;
fibrin modulating drug;
neuroprotective agent;
platelet aggregation inhibitor;
vasodilator agent
dipyridamoledipyridamole : A pyrimidopyrimidine that is 2,2',2'',2'''-(pyrimido[5,4-d]pyrimidine-2,6-diyldinitrilo)tetraethanol substituted by piperidin-1-yl groups at positions 4 and 8 respectively. A vasodilator agent, it inhibits the formation of blood clots.

Dipyridamole: A phosphodiesterase inhibitor that blocks uptake and metabolism of adenosine by erythrocytes and vascular endothelial cells. Dipyridamole also potentiates the antiaggregating action of prostacyclin. (From AMA Drug Evaluations Annual, 1994, p752)
piperidines;
pyrimidopyrimidine;
tertiary amino compound;
tetrol
adenosine phosphodiesterase inhibitor;
EC 3.5.4.4 (adenosine deaminase) inhibitor;
platelet aggregation inhibitor;
vasodilator agent
etazolateetazolate : A pyrazolopyridine that is 1H-pyrazolo[3,4-b]pyridine which is substituted at positions 1, 4, and 5 by ethyl, 2-isopropylidenehydrazino, and ethoxycarbonyl groups, respectively. A phosphodiesterase IV inhibitor with antidepressant and anxiolytic properties.

Etazolate: A potent phosphodiesterase inhibitor proposed as an antipsychotic agent.
ethyl ester;
hydrazone;
pyrazolopyridine
alpha-secretase activator;
antidepressant;
antipsychotic agent;
anxiolytic drug;
GABA agent;
neuroprotective agent;
phosphodiesterase IV inhibitor
amrinoneamrinone : A 3,4'-bipyridine substituted at positions 5 and 6 by an amino group and a keto function respectively. A pyridine phosphodiesterase 3 inhibitor, it is a drug that may improve the prognosis in patients with congestive heart failure.

Amrinone: A positive inotropic cardiotonic (CARDIOTONIC AGENTS) with vasodilator properties, phosphodiesterase 3 inhibitory activity, and the ability to stimulate calcium ion influx into the cardiac cell.
bipyridinesEC 3.1.4.* (phosphoric diester hydrolase) inhibitor
1-methyl-3-isobutylxanthine1-Methyl-3-isobutylxanthine: A potent cyclic nucleotide phosphodiesterase inhibitor; due to this action, the compound increases cyclic AMP and cyclic GMP in tissue and thereby activates CYCLIC NUCLEOTIDE-REGULATED PROTEIN KINASES

3-isobutyl-1-methylxanthine : An oxopurine that is xanthine which is substituted at positions 1 and 3 by methyl and isobutyl groups, respectively.
3-isobutyl-1-methylxanthine
losartanlosartan : A biphenylyltetrazole where a 1,1'-biphenyl group is attached at the 5-position and has an additional trisubstituted imidazol-1-ylmethyl group at the 4'-position

Losartan: An antagonist of ANGIOTENSIN TYPE 1 RECEPTOR with antihypertensive activity due to the reduced pressor effect of ANGIOTENSIN II.
biphenylyltetrazole;
imidazoles
angiotensin receptor antagonist;
anti-arrhythmia drug;
antihypertensive agent;
endothelin receptor antagonist
2-(4-morpholinyl)-8-phenyl-4h-1-benzopyran-4-one2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one: specific inhibitor of phosphatidylinositol 3-kinase; structure in first sourcechromones;
morpholines;
organochlorine compound
autophagy inhibitor;
EC 2.7.1.137 (phosphatidylinositol 3-kinase) inhibitor;
geroprotector
milrinonebipyridines;
nitrile;
pyridone
cardiotonic drug;
EC 3.1.4.17 (3',5'-cyclic-nucleotide phosphodiesterase) inhibitor;
platelet aggregation inhibitor;
vasodilator agent
papaverinepapaverine : A benzylisoquinoline alkaloid that is isoquinoline substituted by methoxy groups at positions 6 and 7 and a 3,4-dimethoxybenzyl group at position 1. It has been isolated from Papaver somniferum.

Papaverine: An alkaloid found in opium but not closely related to the other opium alkaloids in its structure or pharmacological actions. It is a direct-acting smooth muscle relaxant used in the treatment of impotence and as a vasodilator, especially for cerebral vasodilation. The mechanism of its pharmacological actions is not clear, but it apparently can inhibit phosphodiesterases and it may have direct actions on calcium channels.
benzylisoquinoline alkaloid;
dimethoxybenzene;
isoquinolines
antispasmodic drug;
vasodilator agent
proxyphyllineoxopurine
4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone: Inhibitor of phosphodiesterases.methoxybenzenes
roliprampyrrolidin-2-onesantidepressant;
EC 3.1.4.* (phosphoric diester hydrolase) inhibitor
sulmazolesulmazole : An imidazopyridine that is 1H-imidazo[4,5-b]pyridine which is substituted at position 2 by a 2-methoxy-4-(methylsulfinyl)phenyl group. An A1 adenosine receptor antagonist, it was formerly used as a cardiotonic agent.

sulmazole: structure given in first source
imidazopyridine;
sulfoxide
adenosine A1 receptor antagonist;
cardiotonic drug;
EC 3.1.4.* (phosphoric diester hydrolase) inhibitor
vesnarinoneorganic molecular entity
zardaverinezardaverine : A pyridazinone derivative in which pyridazin-3(2H)-one is substituted at C-6 with a 4-(difluoromethoxy)-3-methoxyphenyl group. It is a phosphodiesterase inhibitor, selective for PDE3 and 4.

zardaverine: structure given in first source
organofluorine compound;
pyridazinone
anti-asthmatic drug;
bronchodilator agent;
EC 3.1.4.* (phosphoric diester hydrolase) inhibitor;
peripheral nervous system drug
9-benzyladenine
tetradecanoylphorbol acetatephorbol 13-acetate 12-myristate : A phorbol ester that is phorbol in which the hydroxy groups at the cyclopropane ring juction (position 13) and the adjacent carbon (position 12) have been converted into the corresponding acetate and myristate esters. It is a major active constituent of the seed oil of Croton tiglium. It has been used as a tumour promoting agent for skin carcinogenesis in rodents and is associated with increased cell proliferation of malignant cells. However its function is controversial since a decrease in cell proliferation has also been observed in several cancer cell types.

phorbol ester : Esters of phorbol, originally found in croton oil (from Croton tiglium, of the family Euphorbiaceae). A number of phorbol esters possess activity as tumour promoters and activate the mechanisms associated with cell growth. Some of these are used in experiments as activators of protein kinase C.

Tetradecanoylphorbol Acetate: A phorbol ester found in CROTON OIL with very effective tumor promoting activity. It stimulates the synthesis of both DNA and RNA.
acetate ester;
diester;
phorbol ester;
tertiary alpha-hydroxy ketone;
tetradecanoate ester
antineoplastic agent;
apoptosis inducer;
carcinogenic agent;
mitogen;
plant metabolite;
protein kinase C agonist;
reactive oxygen species generator
eg 626phthalazinol: RN given refers to parent cpd; do not confuse with phthalazinol: 62054-23-3; thromboxane A2 antagonistphthalazines
enoximoneEnoximone: A selective phosphodiesterase inhibitor with vasodilating and positive inotropic activity that does not cause changes in myocardial oxygen consumption. It is used in patients with CONGESTIVE HEART FAILURE.aromatic ketone
piroximonepiroximone: structure in first source
2-(2-methoxy-4-(methylsulfinyl)phenyl)-1h-imidazo(4,5-c)pyridine2-(2-methoxy-4-(methylsulfinyl)phenyl)-1H-imidazo(4,5-c)pyridine: RN & structure given in first source; RN given refers to parent cpd; closely related to sulmazoleimidazoles
imazodanimazodan: RN & structure given in first source;
nitraquazonenitraquazone: structure given in first source
tadalafilbenzodioxoles;
pyrazinopyridoindole
EC 3.1.4.35 (3',5'-cyclic-GMP phosphodiesterase) inhibitor;
vasodilator agent
6-bromo-8-methylaminoimidazo(1,2-a)pyrazine-2-carbonitrile6-bromo-8-methylaminoimidazo(1,2-a)pyrazine-2-carbonitrile: a smooth muscle relaxant that opens potassium channels
y 590
9-(2-hydroxy-3-nonyl)adenine(2R,3S)-EHNA : EHNA of absolute configuration 2R,3S. Selective inhibitor of cGMP-stimulated phosphodiesterase (PDE2) (IC50 = 0.8 - 4 mM). Also a potent inhibitor of adenosine deaminase.EHNAEC 3.1.4.* (phosphoric diester hydrolase) inhibitor;
EC 3.5.4.4 (adenosine deaminase) inhibitor
9-(2-hydroxy-3-nonyl)adenine(2S,3R)-EHNA : EHNA of absolute configuration 2S,3R.EHNA
cilomilastmethoxybenzenes
rp 73401piclamilast : A monocarboxylic acid amide resulting from the formal condensation of the carboxy group of 3-(cyclopentyloxy)-4-methoxybenzoic acid with the primary amino group of 3,5-dichloropyridin-4-amine.

piclamilast: an antiasthmatic agent and phosphodiesterase 4 inhibitor; structure in first source
aromatic ether;
benzamides;
chloropyridine;
monocarboxylic acid amide
anti-asthmatic drug;
anti-inflammatory agent;
bronchodilator agent;
phosphodiesterase IV inhibitor
8-methoxymethyl-3-isobutyl-1-methylxanthine8-methoxymethyl-3-isobutyl-1-methylxanthine: inhibitor of phosphodiesterase Ioxopurine
vinpocetinevinpocetine: whole issue of Arzneim Forsch (23 articles) discuss this drug; Arzneim Forsch 26(10a);1976; RN given refers to parent cpd with unspecified isomeric designationalkaloidgeroprotector
rolipram(-)-rolipram : The (R)-enantiomer of rolipram.rolipram
roflumilastaromatic ether;
benzamides;
chloropyridine;
cyclopropanes;
organofluorine compound
anti-asthmatic drug;
phosphodiesterase IV inhibitor
4,5-dihydro-6-(4-(imidazol-1-yl)phenyl)-5-methyl-3(2h)-pyridazinone4,5-dihydro-6-(4-(imidazol-1-yl)phenyl)-5-methyl-3(2H)-pyridazinone: RN & structure given in first source
indolidanindolidan: structure given in first source
bemoradanbemoradan: RN & structure given in first source
1,3-dihydro-7,8-dimethyl-2h-imidazo(4,5-b)quinolin-2-one1,3-dihydro-7,8-dimethyl-2H-imidazo(4,5-b)quinolin-2-one: structure given in first source
ci 1044CI 1044: inhibits PDE4; structure in first source
t 1032T 1032: a cyclic GMP phosphodiesterase-5 inhibitor; structure in first source
losartan potassiumErythropoietin: Glycoprotein hormone, secreted chiefly by the KIDNEY in the adult and the LIVER in the FETUS, that acts on erythroid stem cells of the BONE MARROW to stimulate proliferation and differentiation.
pf 04217903quinolines
3-(2,5-dimethoxyphenyl)-6-(3,4-dimethoxyphenyl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazinetriazoles
pf-044189481-(4-fluorobenzoyl)-3-(((6-methoxy-2-naphthyl)oxy)methyl)azetidine-3-carboxylic acid: structure in first source
nitd 609NITD 609: an antimalarial and coccidiostat; structure in first source
an2728crisaborole : A member of the class of benzoxaboroles that is 5-hydroxy-1,3-dihydro-2,1-benzoxaborole in which the phenolic hydrogen has been replaced by a 4-cyanophenyl group. A phosphodiesterase 4 inhibitor that is used for treatment of mild to moderate atopic dermatitis in children and adults.

crisaborole: NSAID, Dermatologic Agent; structure in first source
aromatic ether;
benzoxaborole;
nitrile
antipsoriatic;
non-steroidal anti-inflammatory drug;
phosphodiesterase IV inhibitor
cc-1151-ethyl-7-(2-methyl-6-(1H-1,2,4-triazol-3-yl)pyridin-3-yl)-3,4-dihydropyrazino(2,3-b)pyrazin-2(1H)-one: an mTOR kinase inhibitor; structure in first source
chf6001tanimilast: a phosphodiesterase-4 inhibitor; structure in first source
cyclic gmp3',5'-cyclic GMP : A 3',5'-cyclic purine nucleotide in which the purine nucleobase is specified as guanidine.

Cyclic GMP: Guanosine cyclic 3',5'-(hydrogen phosphate). A guanine nucleotide containing one phosphate group which is esterified to the sugar moiety in both the 3'- and 5'-positions. It is a cellular regulatory agent and has been described as a second messenger. Its levels increase in response to a variety of hormones, including acetylcholine, insulin, and oxytocin and it has been found to activate specific protein kinases. (From Merck Index, 11th ed)
3',5'-cyclic purine nucleotide;
guanyl ribonucleotide
Escherichia coli metabolite;
human metabolite;
mouse metabolite;
plant metabolite;
Saccharomyces cerevisiae metabolite
sildenafilsildenafil : A pyrazolo[4,3-d]pyrimidin-7-one having a methyl substituent at the 1-position, a propyl substituent at the 3-position and a 2-ethoxy-5-[(4-methylpiperazin-1-yl)sulfonyl]phenyl group at the 5-position.piperazines;
pyrazolopyrimidine;
sulfonamide
EC 3.1.4.35 (3',5'-cyclic-GMP phosphodiesterase) inhibitor;
vasodilator agent
zaprinastzaprinast: anaphylaxis inhibitor; structuretriazolopyrimidines
vardenafilvardenafil : The sulfonamide resulting from formal condensation of the sulfo group of 4-ethoxy-3-(5-methyl-7-propylimidazo[5,1-f][1,2,4]triazin-4(1H)-one-2-yl)benzenesulfonic acid and the secondary amino group of 4-ethylpiperazine.imidazotriazine;
N-alkylpiperazine;
N-sulfonylpiperazine
EC 3.1.4.* (phosphoric diester hydrolase) inhibitor;
vasodilator agent
Imidazosagatriazinonepyrazolopyrimidine
bl 4162aanagrelide : A 1,5-dihydroimidazo[2,1-]quinazoline having an oxo substituent at the 2-position and chloro substituents at the 6- and 7-positions.

anagrelide: imidazoquinazoline derivative which lowers platelet count probably by inhibiting thrombopoiesis and reduces platelet aggregation; used for thrombocythemia; structure in first source
imidazoquinazolineanticoagulant;
antifibrinolytic drug;
cardiovascular drug;
platelet aggregation inhibitor
1,5-dihydro-7-(1-piperidinyl)-imidazo(2,1-b)quinazolin-2(3h)-one1,5-dihydro-7-(1-piperidinyl)-imidazo(2,1-b)quinazolin-2(3H)-one: a potent inhibitor of platelet aggregation
quazinone
lixazinonelixazinone: structure given in first source