Biomaterial Database

Tetrahydropterins interfere with the G protein pathway in Dictyostelium discoideum. 1996

I Ziegler, and M Gütlich

GSF-Institut für Klinische Molekularbiologie und Tumorgenetik, München, Germany.

The cellular slime mold Dictyostelium discoideum produces tetrahydrodictyopterin, the D-threo-isomer of tetrahydrobiopterin. During cyclic AMP coordinated aggregation, the G protein linked signalling pathway is involved in the regulation of the initial enzyme GTP cyclohydrolase I [M. Gütlich et al., Biochem. J. 314, 95-101 (1996)]. We now find that cyclic AMP stimulated binding of GTPgammaS to the membrane fraction is inhibited by tetrahydrodictyopterin and tetrahydrobiopterin. Inhibition was a function of GTPgammaS concentration and the analysis of the kinetic data pointed to a competitive type of inhibition. The inhibition of G protein activation was accompanied by a loss of adenylyl cyclase activation. Because the GTPgammaS- and G protein-dependent reduction of receptor affinity for cyclic AMP was also attenuated, we conclude that tetrahydrodictyopterin and tetrahydrobiopterin interfere with activation of G proteins by inhibiting GDP-GTP exchange.

UI	MeSH Term	Description	Entries
D004023	Dictyostelium	A genus of protozoa, formerly also considered a fungus. Its natural habitat is decaying forest leaves, where it feeds on bacteria. D. discoideum is the best-known species and is widely used in biomedical research.	Dictyostelium discoideum,Dictyostelium discoideums,Dictyosteliums,discoideum, Dictyostelium
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D000242	Cyclic AMP	An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.	Adenosine Cyclic 3',5'-Monophosphate,Adenosine Cyclic 3,5 Monophosphate,Adenosine Cyclic Monophosphate,Adenosine Cyclic-3',5'-Monophosphate,Cyclic AMP, (R)-Isomer,Cyclic AMP, Disodium Salt,Cyclic AMP, Monoammonium Salt,Cyclic AMP, Monopotassium Salt,Cyclic AMP, Monosodium Salt,Cyclic AMP, Sodium Salt,3',5'-Monophosphate, Adenosine Cyclic,AMP, Cyclic,Adenosine Cyclic 3',5' Monophosphate,Cyclic 3',5'-Monophosphate, Adenosine,Cyclic Monophosphate, Adenosine,Cyclic-3',5'-Monophosphate, Adenosine,Monophosphate, Adenosine Cyclic
D000262	Adenylyl Cyclases	Enzymes of the lyase class that catalyze the formation of CYCLIC AMP and pyrophosphate from ATP.	Adenyl Cyclase,Adenylate Cyclase,3',5'-cyclic AMP Synthetase,Adenylyl Cyclase,3',5' cyclic AMP Synthetase,AMP Synthetase, 3',5'-cyclic,Cyclase, Adenyl,Cyclase, Adenylate,Cyclase, Adenylyl,Cyclases, Adenylyl,Synthetase, 3',5'-cyclic AMP
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001708	Biopterins	Pterin derivatives based on 2-amino-6-(1,2-dihydroxypropyl)-4(1H)-pteridinone. Biopterins are natural products that have been considered as growth factors for some insects. Biopterins are cofactors for the AROMATIC AMINO ACID hydroxylases and NITRIC OXIDE SYNTHASE. Deficiencies in BIOPTERINS metabolism (e.g., lowered TETRAHYDROBIOPTERIN) are associated with neurological deterioration (e.g., HYPERPHENYLALANINAEMIA).	2-Amino-6-((1S,2R)-1,2-dihydroxypropyl)-4(1H)-pteridinone,2-Amino-6-((1S,2S)-1,2-dihydroxypropyl)-4(1H)-pteridinone,2-Amino-6-(1,2-dihydroxypropyl)-4(8H)-pteridinone,2-amino-6-((1R,2R)-1,2-dihydroxypropyl)-4(3H)-pteridinone,4(1H)-Pteridinone, 2-amino-6-(1,2-dihydroxypropyl)-, (S-(R,S))-,6-Biopterin,Biopterin,D-threo-Biopterin,L-Biopterin,L-erythro-Biopterin,L-threo-Biopterin,2-Amino-6-(1,2-dihydroxypropyl)-4(1H)-pteridinone,Dictyopterin,Orinapterin,6 Biopterin,D threo Biopterin,L Biopterin,L erythro Biopterin,L threo Biopterin
D016244	Guanosine 5'-O-(3-Thiotriphosphate)	Guanosine 5'-(trihydrogen diphosphate), monoanhydride with phosphorothioic acid. A stable GTP analog which enjoys a variety of physiological actions such as stimulation of guanine nucleotide-binding proteins, phosphoinositide hydrolysis, cyclic AMP accumulation, and activation of specific proto-oncogenes.	GTP gamma S,Guanosine 5'-(gamma-S)Triphosphate,gamma-Thio-GTP,GTPgammaS,Guanosine 5'-(3-O-Thio)Triphosphate,gamma S, GTP,gamma Thio GTP
D019204	GTP-Binding Proteins	Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.	G-Proteins,GTP-Regulatory Proteins,Guanine Nucleotide Regulatory Proteins,G-Protein,GTP-Binding Protein,GTP-Regulatory Protein,Guanine Nucleotide Coupling Protein,G Protein,G Proteins,GTP Binding Protein,GTP Binding Proteins,GTP Regulatory Protein,GTP Regulatory Proteins,Protein, GTP-Binding,Protein, GTP-Regulatory,Proteins, GTP-Binding,Proteins, GTP-Regulatory