Target type: molecularfunction
Enables the transfer of guanine, 2-amino-6-hydroxypurine, from one side of a membrane to the other. [GOC:go_curators]
Guanine transmembrane transporter activity involves the facilitated movement of guanine across cellular membranes. This process is essential for maintaining the appropriate intracellular concentration of guanine, a purine base that serves as a precursor for the synthesis of guanine nucleotides, such as GTP and GDP. These nucleotides are essential for a wide range of cellular processes, including signal transduction, protein synthesis, and energy metabolism. Guanine transmembrane transporters are typically integral membrane proteins that possess specific binding sites for guanine. Upon binding, the transporter undergoes conformational changes that allow guanine to move from one side of the membrane to the other. The direction of movement can be passive, driven by the concentration gradient of guanine, or active, requiring energy expenditure to move guanine against its concentration gradient. The precise mechanism of transport varies depending on the specific transporter and its associated regulatory factors. These transporters play a critical role in maintaining cellular homeostasis by ensuring an adequate supply of guanine for nucleotide biosynthesis and other cellular processes. Dysregulation of guanine transmembrane transporter activity can lead to various cellular defects and diseases.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Equilibrative nucleoside transporter 1 | An equilibrative nucleoside transporter 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q99808] | Homo sapiens (human) |
| Equilibrative nucleoside transporter 2 | An equilibrative nucleoside transporter 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q14542] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| dilazep | dilazep : A member of the class of diazepanes that is 1,4-diazepane substituted by 3-[(3,4,5-trimethoxybenzoyl)oxy]propyl groups at positions 1 and 4. It is a potent adenosine uptake inhibitor that exhibits antiplatelet, antianginal and vasodilator properties. Dilazep: Coronary vasodilator with some antiarrhythmic activity. | benzoate ester; diazepane; diester; methoxybenzenes | cardioprotective agent; platelet aggregation inhibitor; vasodilator agent |
| dipyridamole | dipyridamole : 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 |
| lidoflazine | Lidoflazine: Coronary vasodilator with some antiarrhythmic action. | diarylmethane | |
| uridine | uridines | drug metabolite; fundamental metabolite; human metabolite | |
| phlorhizin | aryl beta-D-glucoside; dihydrochalcones; monosaccharide derivative | antioxidant; plant metabolite | |
| methylthioinosine | Methylthioinosine: 6-(Methylthio)-9-beta-D-ribofuranosylpurine. An analog of inosine with a methylthio group replacing the hydroxyl group in the 6-position. | purine ribonucleoside; thiopurine | |
| hyaluronoglucosaminidase | kinetin riboside: preferentially induces apoptosis by modulating Bcl-2 family proteins and caspase-3 in cancer cells; structure in first source | purine nucleoside | |
| gemcitabine | gemcitabine : A 2'-deoxycytidine having geminal fluoro substituents in the 2'-position. An inhibitor of ribonucleotide reductase, gemcitabine is used in the treatment of various carcinomas, particularly non-small cell lung cancer, pancreatic cancer, bladder cancer and breast cancer. | organofluorine compound; pyrimidine 2'-deoxyribonucleoside | antimetabolite; antineoplastic agent; antiviral drug; DNA synthesis inhibitor; EC 1.17.4.1 (ribonucleoside-diphosphate reductase) inhibitor; environmental contaminant; immunosuppressive agent; photosensitizing agent; prodrug; radiosensitizing agent; xenobiotic |
| draflazine | draflazine: a nucleoside transport inhibitor; has cardioprotective effect; draflazine is the (-)-enantiomer; R 88016 is the (+)-enantiomer | ||
| adenosine | quinquefolan B: isolated from roots of Panax quinquefolium L.; RN not in Chemline 10/87; RN from Toxlit | adenosines; purines D-ribonucleoside | analgesic; anti-arrhythmia drug; fundamental metabolite; human metabolite; vasodilator agent |
| 4-nitrobenzylthioinosine | 4-nitrobenzylthioinosine: inhibitor of nucleoside transport; acts on ENT1 | purine nucleoside | |
| n(6)-benzyladenosine | N(6)-benzyladenosine: RN given refers to parent cpd | ||
| 6-(4-nitrobenzylthio)guanosine | 6-(4-nitrobenzylthio)guanosine: inhibitor of nucleoside transport | ||
| 5-iodotubercidin | 7-iodotubercidin: inhibits Toxoplasma gondii adenosine kinase | organoiodine compound | |
| n(6)-phenyladenosine | purine nucleoside | ||
| tecadenoson | tecadenoson: an A1 adenosine receptor agonist | ||
| 2-hydroxy-5-nitrobenzylthioguanosine | |||
| n(6)-cyclopentyladenosine | |||
| 6-benzylthioinosine | 6-benzylthioinosine: a subversive substrate of T gondii adenosine kinase; structure in first source |