high-affinity sodium:dicarboxylate symporter activity
Definition
Target type: molecularfunction
Enables the transfer of a solute or solutes from one side of a membrane to the other according to the reaction: dicarboxylate(out) + Na+(out) = dicarboxylate(in) + Na+(in). In high-affinity transport the transporter is able to bind the solute even if it is only present at very low concentrations. [TC:2.A.47.1.4]
High-affinity sodium:dicarboxylate symporters are integral membrane proteins responsible for the transmembrane transport of dicarboxylates, a class of organic molecules characterized by the presence of two carboxyl groups. These transporters operate through a coupled mechanism, utilizing the electrochemical gradient of sodium ions (Na+) to drive the uphill movement of dicarboxylates across the cell membrane.
The process begins with the binding of both Na+ and the dicarboxylate substrate to the transporter protein on the extracellular side of the membrane. This binding event triggers a conformational change in the transporter, exposing the binding sites to the intracellular environment. The Na+ ions then move down their electrochemical gradient, from the extracellular to the intracellular compartment. This movement provides the energy required for the simultaneous transport of the dicarboxylate against its concentration gradient.
The sodium:dicarboxylate symporters exhibit high affinity for their substrates, ensuring efficient uptake even at low concentrations. This feature is crucial for cellular processes such as the import of essential metabolites like succinate, malate, and fumarate. These dicarboxylates play vital roles in cellular respiration, gluconeogenesis, and other metabolic pathways.
Furthermore, the activity of these transporters is regulated by various factors, including the availability of Na+, the intracellular concentration of dicarboxylates, and the presence of specific inhibitors. This intricate regulation ensures the proper balance of substrate uptake and utilization within the cell.'
"
Proteins (2)
| Protein | Definition | Taxonomy |
|---|---|---|
| Solute carrier family 13 member 3 | A Na(+)/dicarboxylate cotransporter 3 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q8WWT9] | Homo sapiens (human) |
| Solute carrier family 13 member 3 | A Na(+)/dicarboxylate cotransporter 3 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q8WWT9] | Homo sapiens (human) |
Compounds (1)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| succinic acid | succinic acid : An alpha,omega-dicarboxylic acid resulting from the formal oxidation of each of the terminal methyl groups of butane to the corresponding carboxy group. It is an intermediate metabolite in the citric acid cycle. Succinic Acid: A water-soluble, colorless crystal with an acid taste that is used as a chemical intermediate, in medicine, the manufacture of lacquers, and to make perfume esters. It is also used in foods as a sequestrant, buffer, and a neutralizing agent. (Hawley's Condensed Chemical Dictionary, 12th ed, p1099; McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1851) | alpha,omega-dicarboxylic acid; C4-dicarboxylic acid | anti-ulcer drug; fundamental metabolite; micronutrient; nutraceutical; radiation protective agent |