protein N-linked glycosylation

Definition

Target type: biologicalprocess

A protein glycosylation process in which a carbohydrate or carbohydrate derivative unit is added to a protein via the N4 atom of peptidyl-asparagine, the omega-N of arginine, or the N1' atom peptidyl-tryptophan. [GOC:pr, RESID:AA0151, RESID:AA0156, RESID:AA0327]

N-linked glycosylation is a complex and essential process in the biosynthesis of proteins. It involves the attachment of a branched oligosaccharide chain, called an N-glycan, to the nitrogen atom of an asparagine residue within a protein. This process takes place in the endoplasmic reticulum (ER), a cellular organelle involved in protein folding and modification.

The N-glycan precursor, a preassembled oligosaccharide consisting of 14 sugar residues, is synthesized on a lipid carrier called dolichol phosphate. This precursor is then transferred en bloc to the asparagine residue within a specific sequence motif in the protein, typically Asn-X-Ser/Thr, where X can be any amino acid except proline. This transfer reaction is catalyzed by an enzyme called oligosaccharyltransferase (OST).

After the transfer of the N-glycan, the protein undergoes further processing and modifications in the ER and Golgi apparatus, which involves the removal of some sugars and the addition of others. The specific composition of the N-glycan can vary depending on the protein and the cell type.

The N-glycans play crucial roles in various biological functions, including:

- Protein folding and stability: N-glycosylation can contribute to the proper folding and stability of proteins by influencing their conformation and interactions.
- Protein targeting and trafficking: N-glycans can act as signals that direct proteins to specific locations within the cell.
- Cell-cell interactions: N-glycans can participate in interactions between cells and the extracellular matrix.
- Immune recognition: N-glycans can modulate the immune response by influencing the recognition of proteins by immune cells.

In summary, N-linked glycosylation is a fundamental biological process that plays a vital role in the structure, function, and regulation of proteins. The intricate modifications of N-glycans ensure proper protein folding, trafficking, and interactions, contributing to the diverse functions of proteins in cellular processes and biological systems.'
"

Proteins (9)

Compounds (27)