sialylation
Definition
Target type: biologicalprocess
The covalent attachment of sialic acid to a substrate molecule. [GOC:cjm]
Sialylation is a critical post-translational modification that involves the addition of sialic acid, a negatively charged monosaccharide, to terminal positions of glycans on glycoproteins and glycolipids. This process is catalyzed by a family of enzymes called sialyltransferases, which exhibit specificity for both the donor substrate (CMP-sialic acid) and the acceptor substrate (glycan). Sialylation plays a crucial role in a wide range of biological functions, including cell-cell recognition, immune response modulation, inflammation, and development.
The sialylation process begins with the activation of sialic acid by the enzyme CMP-sialic acid synthetase, which converts sialic acid into its nucleotide-activated form, CMP-sialic acid. This activated form serves as the donor substrate for sialyltransferases. Sialyltransferases then utilize CMP-sialic acid to transfer sialic acid to the terminal galactose or N-acetylglucosamine residues of glycans. The specificity of sialyltransferases is determined by the acceptor substrate, which can be a specific glycan structure or a specific protein.
Sialylation plays a key role in cell-cell recognition and signaling by modifying the surface properties of cells. For example, sialic acid residues on glycoproteins and glycolipids can interact with lectins, which are carbohydrate-binding proteins that mediate cell adhesion and signaling. Sialylation also plays a crucial role in the immune response by influencing the interaction of immune cells with their target cells. For example, sialylation can modulate the recognition of antigens by antibodies and the activation of immune cells.
In addition to its role in cell-cell recognition and immune response, sialylation is also involved in a variety of other biological processes, including inflammation, development, and disease. For example, sialylation has been implicated in the development of cancer and in the progression of inflammatory diseases.
Sialylation is a complex and highly regulated process that is essential for proper cell function and development. The precise roles of sialylation in different biological contexts are still being investigated, but it is clear that this modification has a profound impact on cellular physiology.'
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Proteins (2)
| Protein | Definition | Taxonomy |
|---|---|---|
| CMP-N-acetylneuraminate-beta-galactosamide-alpha-2,3-sialyltransferase 1 | A CMP-N-acetylneuraminate-beta-galactosamide-alpha-2,3-sialyltransferase 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q11201] | Homo sapiens (human) |
| Beta-galactoside alpha-2,6-sialyltransferase 1 | A beta-galactoside alpha-2,6-sialyltransferase 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P15907] | Homo sapiens (human) |
Compounds (12)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| 2,3-dihydroxybenzoic acid | 2,3-dihydroxybenzoic acid : A dihydroxybenzoic acid that is benzoic acid substituted by hydroxy groups at positions 2 and 3. It occurs naturally in Phyllanthus acidus and in the aquatic fern Salvinia molesta. 2,3-dihydroxybenzoic acid: RN given refers to parent cpd dihydroxybenzoic acid : Any member of the class of hydroxybenzoic acids carrying two phenolic hydroxy groups on the benzene ring and its derivatives. | dihydroxybenzoic acid | human xenobiotic metabolite; plant metabolite |
| protocatechuic acid | 3,4-dihydroxybenzoic acid : A dihydroxybenzoic acid in which the hydroxy groups are located at positions 3 and 4. protocatechuic acid: RN given refers to parent cpd; structure | catechols; dihydroxybenzoic acid | antineoplastic agent; EC 1.1.1.25 (shikimate dehydrogenase) inhibitor; EC 1.14.11.2 (procollagen-proline dioxygenase) inhibitor; human xenobiotic metabolite; plant metabolite |
| gallic acid | gallate : A trihydroxybenzoate that is the conjugate base of gallic acid. | trihydroxybenzoic acid | antineoplastic agent; antioxidant; apoptosis inducer; astringent; cyclooxygenase 2 inhibitor; EC 1.13.11.33 (arachidonate 15-lipoxygenase) inhibitor; geroprotector; human xenobiotic metabolite; plant metabolite |
| beta-resorcylic acid | beta-resorcylic acid: RN given refers to parent cpd; structure | ||
| 2,5-dihydroxybenzoic acid | 2,5-dihydroxybenzoic acid : A dihydroxybenzoic acid having the two hydroxy groups at the 2- and 5-positions. 2,5-dihydroxybenzoic acid: RN given refers to parent cpd; a oxidative product of saligenin | dihydroxybenzoic acid | EC 1.13.11.33 (arachidonate 15-lipoxygenase) inhibitor; fungal metabolite; human metabolite; MALDI matrix material; mouse metabolite |
| veratric acid | 3,4-dimethoxybenzoic acid : A member of the class of benzoic acids that is benzoic acid substituted by methoxy groups at positions 2 and 3. veratric acid: RN given refers to parent cpd; structure | benzoic acids | allergen; plant metabolite |
| methyl gallate | methyl 3,4,5-trihydroxybenzoate : A gallate ester obtained by the formal condensation of gallic acid with methanol. It exhibits anti-oxidant, anti-tumor, anti-microbial and anti-inflammatory properties. methyl gallate: has both immunosuppressive and phytogenic antineoplastic activities; isolated from Acer saccharinum | gallate ester | anti-inflammatory agent; antioxidant; plant metabolite |
| 3,4,5-trimethoxybenzoic acid | 3,4,5-trimethoxybenzoic acid : A benzoic acid derivative carrying 3-, 4- and 5-methoxy substituents. 3,4,5-trimethoxybenzoic acid: RN given refers to parent cpd; structure | benzoic acids; methoxybenzenes | human urinary metabolite; human xenobiotic metabolite; plant metabolite |
| syringic acid | syringic acid : A dimethoxybenzene that is 3,5-dimethyl ether derivative of gallic acid. syringic acid: RN given refers to parent cpd; structure in third source | benzoic acids; dimethoxybenzene; phenols | plant metabolite |
| epigallocatechin gallate | (-)-epigallocatechin 3-gallate : A gallate ester obtained by the formal condensation of gallic acid with the (3R)-hydroxy group of (-)-epigallocatechin. epigallocatechin gallate: a steroid 5alpha-reductase inhibitor and antimutagen in green tea (Camellia sinensis) | flavans; gallate ester; polyphenol | antineoplastic agent; antioxidant; apoptosis inducer; geroprotector; Hsp90 inhibitor; neuroprotective agent; plant metabolite |
| cytidine monophosphate n-acetylneuraminic acid | CMP-N-acetyl-beta-neuraminic acid : A nucleotide sugar used as a donor by glycosyltransferases for the synthesis of sugar chains Cytidine Monophosphate N-Acetylneuraminic Acid: A nucleoside monophosphate sugar which donates N-acetylneuraminic acid to the terminal sugar of a ganglioside or glycoprotein. | CMP-N-acyl-beta-neuraminic acid | mouse metabolite |
| guanosine diphosphate | Guanosine Diphosphate: A guanine nucleotide containing two phosphate groups esterified to the sugar moiety. | guanosine 5'-phosphate; purine ribonucleoside 5'-diphosphate | Escherichia coli metabolite; mouse metabolite; uncoupling protein inhibitor |