A4GNT - Alpha-1,4-N-Acetylglucosaminyltransferase |Elisa - Clia - Antibody - Protein

Background:

A4GNT belongs to the glycosyltransferase family, specifically the glycosyltransferase 49 family. It is primarily expressed in the stomach mucosa, particularly in gastric glands and pyloric glands. The gene encoding A4GNT is located on chromosome 3q27.Alpha-1,4-N-Acetylglucosaminyltransferase 4, also known as A4GNT is a, member of the glycosyltransferase 32 family of proteins (GT´s). A4GNT catalyzes the transfer of N-acetylglucosamine (GlcNAc) to core 2 branched O-glycans. A4GNT is a single-pass type II membrane protein associated with the Golgi apparatus and contains the conserved DXD motif involved in catalytic activity

Function:

A4GNT catalyzes the transfer of N-acetylglucosamine (GlcNAc) to the terminal beta-linked galactose residue of glycoproteins or glycolipids. This enzymatic activity is crucial for the biosynthesis of mucin-type O-glycans, which are abundant in the mucous layer of the gastrointestinal tract. Specifically, A4GNT is involved in the biosynthesis of the blood group H antigen, which serves as a precursor for the synthesis of ABO and Lewis blood group antigens.

Main Features:

• Substrate Specificity: A4GNT specifically transfers GlcNAc to the terminal galactose residue of glycoproteins or glycolipids.
• Tissue Specificity: While expressed in the stomach mucosa, A4GNT is absent or expressed at low levels in other tissues.
• Post-translational Modification: A4GNT-mediated glycosylation plays a significant role in modifying the properties of proteins, influencing their stability, solubility, and interactions with other molecules.

Biological Significance:

1. Gastrointestinal Health: A4GNT is crucial for maintaining the integrity and function of the gastric mucosa. It contributes to the formation of the protective mucous layer that shields the stomach epithelium from damage caused by acidic gastric juices and mechanical stress.
2. Blood Group Antigen Formation: A4GNT is involved in the synthesis of the H antigen, which serves as a precursor for the synthesis of ABO and Lewis blood group antigens. These antigens play important roles in blood transfusion compatibility and immune responses.
3. Cell Signaling: Glycosylation mediated by A4GNT can influence cell signaling pathways by modulating the interactions between glycoproteins and their ligands, thereby regulating various physiological processes such as cell adhesion, migration, and differentiation.

Clinical Issues:

• Gastric Diseases: Dysregulation of A4GNT expression or activity has been implicated in various gastric diseases, including gastric cancer and peptic ulcers. Abnormal glycosylation patterns resulting from A4GNT dysfunction can compromise the protective function of the gastric mucosa, predisposing individuals to tissue damage and disease development.
• Blood Group Disorders: Mutations affecting A4GNT activity can lead to alterations in blood group antigen expression, potentially causing blood transfusion incompatibility or influencing susceptibility to certain diseases.
• Diagnostic and Therapeutic Potential: A4GNT and its associated glycosylation pathways have emerged as potential targets for the development of diagnostic biomarkers and therapeutic interventions for gastric diseases and other conditions associated with aberrant glycosylation patterns.