glycosylation
Definition
Target type: biologicalprocess
The covalent attachment and further modification of carbohydrate residues to a substrate molecule. [GOC:hjd, GOC:mah]
Glycosylation is a fundamental biological process that involves the addition of carbohydrate molecules, known as glycans, to proteins or lipids. This modification significantly influences the structure, function, and fate of these biomolecules. The process is catalyzed by enzymes known as glycosyltransferases, which transfer specific sugars from donor molecules to acceptor molecules.
Glycosylation occurs in the endoplasmic reticulum (ER) and Golgi apparatus of eukaryotic cells. The process can be broadly classified into two main types: N-glycosylation and O-glycosylation.
N-glycosylation involves the attachment of a complex oligosaccharide to the nitrogen atom of an asparagine residue within a specific consensus sequence (Asn-X-Ser/Thr) in a protein. The oligosaccharide precursor is assembled in the ER and then transferred en bloc to the protein. This process is initiated by the synthesis of a lipid-linked oligosaccharide precursor, GlcNAc2Man9Glc3, on a dolichol phosphate carrier. Subsequently, this precursor undergoes a series of modifications, including trimming and the addition of additional sugars, before being transferred to the protein.
O-glycosylation involves the attachment of sugars to the oxygen atom of serine or threonine residues in a protein. This type of glycosylation is more diverse than N-glycosylation, with a wide variety of sugar modifications and branching patterns. O-glycosylation is often initiated by the addition of N-acetylgalactosamine (GalNAc) to a serine or threonine residue. Further modifications can then occur, depending on the specific protein and cell type.
Glycosylation plays crucial roles in various cellular processes, including:
- Protein folding and stability: Glycans can promote proper protein folding and prevent aggregation.
- Cell-cell interactions: Glycans mediate interactions between cells, allowing them to recognize and communicate with each other.
- Immune response: Glycosylation is involved in the recognition of pathogens by the immune system.
- Signal transduction: Glycans can influence the activation and signaling of various receptors.
- Protein trafficking: Glycans can direct proteins to their specific locations within the cell.
Disruptions in glycosylation can lead to a variety of diseases, including cancer, genetic disorders, and immune deficiencies. Understanding the complex nature of glycosylation is therefore crucial for developing new therapeutic strategies and diagnostics.'
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Proteins (1)
| Protein | Definition | Taxonomy |
|---|---|---|
| Metabotropic glutamate receptor 7 | A metabotropic glutamate receptor 7 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q14831] | Homo sapiens (human) |
Compounds (21)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| glutamic acid | glutamic acid : An alpha-amino acid that is glutaric acid bearing a single amino substituent at position 2. Glutamic Acid: A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM. | glutamic acid; glutamine family amino acid; L-alpha-amino acid; proteinogenic amino acid | Escherichia coli metabolite; ferroptosis inducer; micronutrient; mouse metabolite; neurotransmitter; nutraceutical |
| quisqualic acid | Quisqualic Acid: An agonist at two subsets of excitatory amino acid receptors, ionotropic receptors that directly control membrane channels and metabotropic receptors that indirectly mediate calcium mobilization from intracellular stores. The compound is obtained from the seeds and fruit of Quisqualis chinensis. | non-proteinogenic alpha-amino acid | |
| plasmenylserine | O-phospho-L-serine : The L-enantiomer of O-phosphoserine. O-phosphoserine : A serine derivative that is serine substituted at the oxygen atom by a phosphono group. plasmenylserine: RN given refers to (L)-isomer | O-phosphoserine | EC 1.4.7.1 [glutamate synthase (ferredoxin)] inhibitor; EC 2.5.1.49 (O-acetylhomoserine aminocarboxypropyltransferase) inhibitor; EC 4.3.1.10 (serine-sulfate ammonia-lyase) inhibitor; Escherichia coli metabolite; human metabolite; mouse metabolite; Saccharomyces cerevisiae metabolite |
| 1-amino-1,3-dicarboxycyclopentane | 1-amino-1,3-dicarboxycyclopentane: RN given refers to (cis)-isomer | ||
| 2-amino-4-phosphonobutyric acid | (2S)-2-amino-4-phosphonobutanoic acid : A non-proteinogenc L-alpha-amino acid that is L-alpha-aminobutyric acid in which one of the hydrogens of the terminal methyl group has been replaced by a dihydroxy(oxido)-lambda(5)-phosphanyl group. It is a potent and selective agonist for the group III metabotropic glutamate receptors (mGluR4/6/7/8). | non-proteinogenic L-alpha-amino acid; phosphonic acids | metabotropic glutamate receptor agonist |
| eglumetad | eglumetad: LY-354740 is the active isomer, LY-366563 is the inactive isomer, and LY 314582 is the racemate; structure given in first source | L-alpha-amino acid | |
| 3,5-dihydroxyphenylglycine | (S)-3,5-dihydroxyphenylglycine : A glycine derivative that is L-alpha-phenylglycine substituted at positions 3 and 5 on the phenyl ring by hydroxy groups. | amino acid zwitterion; non-proteinogenic L-alpha-amino acid; resorcinols | |
| amn082 | N,N'-bis(diphenylmethyl)ethane-1,2-diamine : A diamine that is ethane-1,2-diamine in which both amino groups are substituted by diphenylmethyl groups. It is an allosteric agonist of the metabotropic glutamate receptor 7 (mGluR7). | benzenes; diamine; diarylmethane; secondary amino compound | metabotropic glutamate receptor agonist; neuroprotective agent |
| 6-methyl-2-(phenylethynyl)pyridine | 2-methyl-6-(phenylethynyl)pyridine : A methylpyridine that coinsists of 2-methylp[yridine bearing an additional phenylethynyl group at position 6. Potent and highly selective non-competitive antagonist at the mGlu5 receptor subtype (IC50 = 36 nM) and a positive allosteric modulator at mGlu4 receptors. Centrally active following systemic administration in vivo. Reverses mechanical hyperalgesia in the inflamed rat hind paw. 6-methyl-2-(phenylethynyl)pyridine: an mGlu5 antagonist | acetylenic compound; methylpyridines | anxiolytic drug; metabotropic glutamate receptor antagonist |
| sib 1757 | SIB 1757: a selective mGluR5 antagonist; structure in first source | ||
| l-2-(carboxypropyl)glycine | |||
| 2-(2,3-dicarboxycyclopropyl)glycine | |||
| 2r,4r-4-aminopyrrolidine-2,4-dicarboxylate | pyrrolidinedicarboxylic acid | ||
| sib 1893 | SIB 1893: a selective mGluR5 antagonist; structure in first source | ||
| 1-aminocyclopentane-1,3,4-tricarboxylic acid | 1-aminocyclopentane-1,3,4-tricarboxylic acid: metabolic glutamate receptor (mGluR) antagonist; structure in first source | ||
| ly 341495 | xanthenes | ||
| mgs 0028 | MGS 0028: a group II mGluR agonist; structure in first source | ||
| ly 389795 | LY 389795: a group II metabotropic glutamate receptor agonist; structure in first source | ||
| ly 379268 | LY 379268 : An organic heterobicyclic compound that is (1R,5S)-2-oxabicyclo[3.1.0]hexane carrying amino, carboxy, and carboxy groups at positions 4R, 4R and 6R, respectively. It is a potent agonist of group II metabotropic glutamate receptors mGluR2 and mGluR3 (EC50 = 2.69 nM and 4.48 nM, respectively) that exhibits antipsychotic-like action in animal models of schizophrenia. LY 379268: group II metabotropic glutamate receptor agonist; structure in first source | amino dicarboxylic acid; bridged compound; organic heterobicyclic compound | antipsychotic agent; anxiolytic drug; metabotropic glutamate receptor agonist; neuroprotective agent |
| a 794282 | |||
| 3,4-dicarboxyphenylglycine |