guanine transmembrane transport
Definition
Target type: biologicalprocess
The process in which guanine is transported across a membrane. [GO_REF:0000069, GOC:TermGenie, PMID:14998997]
Guanine transmembrane transport is a complex process that involves the movement of guanine across the cell membrane. Guanine is a purine base that is essential for the synthesis of DNA and RNA. It is also a component of ATP, the primary energy carrier in cells.
The transport of guanine across the cell membrane is mediated by specific transmembrane proteins called guanine transporters. These transporters are highly selective for guanine and do not transport other purine bases or nucleosides.
There are two main types of guanine transporters:
* **Primary active transporters:** These transporters use energy derived from ATP hydrolysis to move guanine against its concentration gradient. This type of transport is called active transport.
* **Secondary active transporters:** These transporters utilize the energy stored in the electrochemical gradient of another molecule to move guanine. This type of transport is called secondary active transport.
The mechanism of guanine transport by primary active transporters is not fully understood. However, it is believed that these transporters bind guanine on one side of the membrane and then use energy from ATP hydrolysis to move the guanine across the membrane to the other side.
Secondary active transporters typically use the electrochemical gradient of sodium or potassium ions to move guanine across the membrane. These transporters bind guanine and a sodium or potassium ion on one side of the membrane. The movement of the sodium or potassium ion down its concentration gradient provides the energy needed to move guanine against its concentration gradient.
Guanine transmembrane transport is essential for many cellular processes. For example, it is required for DNA and RNA synthesis, ATP production, and the synthesis of other important molecules. Dysregulation of guanine transport has been implicated in a variety of diseases, including cancer, neurodegenerative disorders, and genetic disorders.
The transport of guanine across the cell membrane is a highly regulated process. The activity of guanine transporters is regulated by a variety of factors, including the concentration of guanine, the availability of ATP, and the presence of other molecules that can interact with the transporters.
Research on guanine transmembrane transport is ongoing. Scientists are working to understand the mechanisms of transport in more detail, to identify new guanine transporters, and to develop new drugs that target guanine transport.
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Proteins (2)
| 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) |
Compounds (19)
| 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 |