Target type: biologicalprocess
The directed movement of sialic acid into, out of or within a cell, or between cells, by means of some agent such as a transporter or pore. [GOC:krc]
Sialic acid transport is a crucial process in cellular physiology, facilitating the movement of sialic acid across cellular membranes. Sialic acid, a nine-carbon sugar, is a ubiquitous component of glycoconjugates, including glycoproteins and glycolipids, found on the surface of cells and in various biological fluids. Its transport is essential for a multitude of biological functions, including cell signaling, immune recognition, and pathogen interactions.
The transport of sialic acid across membranes is mediated by specific transmembrane proteins called sialic acid transporters. These proteins, often referred to as sialin or solute carrier family 35 (SLC35) members, exhibit distinct structural features and substrate specificities.
One major mechanism of sialic acid transport is facilitated diffusion, where the movement of sialic acid across the membrane is driven by its concentration gradient. Sialin proteins facilitate this process by providing a pathway for sialic acid to cross the membrane without requiring energy expenditure. This is often observed in the Golgi apparatus, where sialic acid is transported from the cytoplasm to the lumen for incorporation into glycoconjugates.
Another mode of sialic acid transport involves active transport, where energy is required to move sialic acid against its concentration gradient. This process is typically mediated by ATP-dependent pumps, which utilize the energy derived from ATP hydrolysis to drive sialic acid transport. Active transport plays a crucial role in the uptake of sialic acid from the extracellular environment, such as the blood or interstitial fluid, into cells.
The transport of sialic acid is tightly regulated, ensuring appropriate levels of this essential sugar in various cellular compartments. This regulation can involve factors such as substrate availability, pH, and the presence of specific cofactors or inhibitors. Disruptions in sialic acid transport have been linked to various disease states, highlighting its importance in maintaining cellular homeostasis.
In summary, sialic acid transport is a complex and regulated process involving dedicated transmembrane proteins that facilitate the movement of this essential sugar across cellular membranes. The transport mechanism can be either facilitated diffusion or active transport, depending on the cellular context. The correct functioning of these transporters is critical for numerous biological processes, and their dysregulation can lead to various pathological conditions.'
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Protein | Definition | Taxonomy |
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Sialin | A sialin that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q9NRA2] | Homo sapiens (human) |
Sialin | A sialin that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q9NRA2] | Homo sapiens (human) |
Compound | Definition | Classes | Roles |
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fr 139317 | FR 139317: endothelin receptor A antagonist; structure given in first source | ||
n-(fluorenyl-9-methoxycarbonyl)leucine | N-(fluorenyl-9-methoxycarbonyl)leucine: a leumedin; RN given for (L)-isomer |