Page last updated: 2024-10-24

nucleoside transmembrane transport

Definition

Target type: biologicalprocess

The directed movement of nucleoside across a membrane. [GOC:pr, GOC:TermGenie]

Nucleoside transmembrane transport is a crucial process that enables cells to acquire essential nucleosides, building blocks of DNA and RNA, from the extracellular environment. This transport is facilitated by specialized proteins embedded in the cell membrane, known as nucleoside transporters. These transporters exhibit high selectivity for specific nucleosides, ensuring that only the necessary molecules are taken up by the cell.

The transport process begins with the binding of a nucleoside to the transporter protein on the extracellular side of the membrane. This interaction induces a conformational change in the protein, opening a passageway through the membrane. The nucleoside then traverses this passageway, moving from the high-concentration extracellular environment to the low-concentration intracellular environment, following the principles of passive diffusion or active transport.

In passive diffusion, the movement of nucleosides across the membrane is driven solely by the concentration gradient, without the need for energy expenditure by the cell. Conversely, active transport utilizes energy, usually derived from ATP hydrolysis, to move nucleosides against their concentration gradient. This allows cells to accumulate high concentrations of specific nucleosides, even when the extracellular concentration is low.

Nucleoside transmembrane transport plays a vital role in various cellular functions, including:

* **DNA and RNA synthesis:** By providing the necessary building blocks for DNA and RNA, nucleoside transport enables cells to replicate their genetic material and synthesize proteins.
* **Signal transduction:** Some nucleosides, like adenosine, act as signaling molecules, mediating crucial cellular processes. Their transport across the membrane allows these molecules to reach their target receptors.
* **Immune response:** Certain nucleosides are involved in the regulation of immune responses, contributing to the body's defense against pathogens.

Dysregulation of nucleoside transport can lead to various health issues, including:

* **Cancer:** Increased nucleoside uptake can fuel tumor cell growth and proliferation.
* **Immune deficiency:** Impaired nucleoside transport can disrupt immune responses, leaving the body susceptible to infections.
* **Neurological disorders:** Dysregulation of nucleoside transport in the brain can contribute to cognitive decline and neurodegenerative diseases.

Therefore, understanding and modulating nucleoside transmembrane transport holds immense therapeutic potential for treating a wide range of diseases.'
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Proteins (6)

ProteinDefinitionTaxonomy
Solute carrier family 28 member 3A solute carrier family 28 member 3 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q9HAS3]Homo sapiens (human)
Equilibrative nucleoside transporter 1An equilibrative nucleoside transporter 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q99808]Homo sapiens (human)
Equilibrative nucleoside transporter 4An equilibrative nucleoside transporter 4 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q7RTT9]Homo sapiens (human)
Equilibrative nucleoside transporter 2An equilibrative nucleoside transporter 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q14542]Homo sapiens (human)
Sodium/nucleoside cotransporter 2A sodium/nucleoside cotransporter 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:O43868]Homo sapiens (human)
Sodium/nucleoside cotransporter 1A sodium/nucleoside cotransporter 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:O00337]Homo sapiens (human)

Compounds (27)

CompoundDefinitionClassesRoles
histaminearalkylamino compound;
imidazoles
human metabolite;
mouse metabolite;
neurotransmitter
dilazepdilazep : 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
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
lidoflazineLidoflazine: Coronary vasodilator with some antiarrhythmic action.diarylmethane
phloretindihydrochalconesantineoplastic agent;
plant metabolite
floxuridinefloxuridine : A pyrimidine 2'-deoxyribonucleoside compound having 5-fluorouracil as the nucleobase; used to treat hepatic metastases of gastrointestinal adenocarcinomas and for palliation in malignant neoplasms of the liver and gastrointestinal tract.

Floxuridine: An antineoplastic antimetabolite that is metabolized to fluorouracil when administered by rapid injection; when administered by slow, continuous, intra-arterial infusion, it is converted to floxuridine monophosphate. It has been used to treat hepatic metastases of gastrointestinal adenocarcinomas and for palliation in malignant neoplasms of the liver and gastrointestinal tract.
nucleoside analogue;
organofluorine compound;
pyrimidine 2'-deoxyribonucleoside
antimetabolite;
antineoplastic agent;
antiviral drug;
radiosensitizing agent
uridineuridinesdrug metabolite;
fundamental metabolite;
human metabolite
phlorhizinaryl beta-D-glucoside;
dihydrochalcones;
monosaccharide derivative
antioxidant;
plant metabolite
resacetophenone2',4'-dihydroxyacetophenone : A dihydroxyacetophenone that is acetophenone carrying hydroxy substituents at positions 2' and 4'.

resacetophenone: structure in first source
dihydroxyacetophenone;
resorcinols
plant metabolite
methylthioinosineMethylthioinosine: 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
hyaluronoglucosaminidasekinetin riboside: preferentially induces apoptosis by modulating Bcl-2 family proteins and caspase-3 in cancer cells; structure in first sourcepurine nucleoside
gemcitabinegemcitabine : 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
draflazinedraflazine: a nucleoside transport inhibitor; has cardioprotective effect; draflazine is the (-)-enantiomer; R 88016 is the (+)-enantiomer
adenosinequinquefolan B: isolated from roots of Panax quinquefolium L.; RN not in Chemline 10/87; RN from Toxlitadenosines;
purines D-ribonucleoside
analgesic;
anti-arrhythmia drug;
fundamental metabolite;
human metabolite;
vasodilator agent
4-nitrobenzylthioinosine4-nitrobenzylthioinosine: inhibitor of nucleoside transport; acts on ENT1purine nucleoside
2,4,6-trihydroxyacetophenone2',4',6'-trihydroxyacetophenone : A benzenetriol that is acetophenone in which the hydrogens at positions 2, 4, and 6 on the phenyl group are replaced by hydroxy groups. It is used as a matrix in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry for the analysis of acidic glycans and glycopeptides.

monoacetylphloroglucinol: structure in first source
aromatic ketone;
benzenetriol;
methyl ketone
MALDI matrix material;
plant metabolite
2,6-dihydroxyacetophenone2,6-dihydroxyacetophenone: inhibits aminopyrine-N-demethylase in rat liver microsomal preparationsaromatic ketone
n(6)-benzyladenosineN(6)-benzyladenosine: RN given refers to parent cpd
6-(4-nitrobenzylthio)guanosine6-(4-nitrobenzylthio)guanosine: inhibitor of nucleoside transport
5-iodotubercidin7-iodotubercidin: inhibits Toxoplasma gondii adenosine kinaseorganoiodine compound
n(6)-phenyladenosinepurine nucleoside
tecadenosontecadenoson: an A1 adenosine receptor agonist
2-hydroxy-5-nitrobenzylthioguanosine
n(6)-cyclopentyladenosine
7,8,3'-trihydroxyflavone7,8,3'-trihydroxyflavone: a potent small molecule TrkB receptor agonist that protects spiral ganglion neurons from degeneration both in vitro and in vivo
trilobatintrilobatin : An aryl beta-D-glucoside that is phloretin attached to a beta-D-glucopyranosyl residue at position 4' via a glycosidic linkage. It is isolated from the leaves of the Chinese sweet tea Lithocarpus polystachyus and exhibits significant anti-hyperglycemic, anti-oxidative and anti-inflammatory properties.

trilobatin: anti-inflammatory from Lithocarpus polystachyus leaves; structure in first source
aryl beta-D-glucoside;
dihydrochalcones;
monosaccharide derivative
anti-inflammatory agent;
antioxidant;
plant metabolite;
sweetening agent
6-benzylthioinosine6-benzylthioinosine: a subversive substrate of T gondii adenosine kinase; structure in first source