A4GALT - Lactosylceramide 4-Alpha-Galactosyltransferase |Elisa - Clia - Antibody - Protein

Background

Lactosylceramide 4-Alpha-Galactosyltransferase, encoded by the A4GALT gene, is an enzyme involved in glycosphingolipid biosynthesis, specifically in the synthesis of glycosphingolipids containing the alpha-galactosyl residue. Catalyzes the transfer of galactose to lactosylceramide to form globotriaosylceramide, which has been identified as the P(k) antigen of the P blood group system. 

Enzymatic Function

A4GALT catalyzes the transfer of a galactose residue from uridine diphosphate (UDP)-galactose to lactosylceramide, a precursor molecule, to form globotriaosylceramide (Gb3) or other glycosphingolipids containing alpha-galactosyl residues. This enzymatic reaction is a crucial step in the biosynthesis of various glycosphingolipids.

Glycosphingolipid Biosynthesis

Glycosphingolipids are complex lipids found in cell membranes and play diverse roles in cell-cell recognition, signal transduction, membrane trafficking, and cell adhesion. The addition of alpha-galactosyl residues to lactosylceramide by A4GALT contributes to the structural diversity and functional complexity of glycosphingolipids. A4GALT is expressed in various tissues and cell types, including the liver, kidney, intestine, and immune cells. Its expression pattern may vary depending on developmental stage, tissue type, and physiological conditions.

Biological Significance

Glycosphingolipids synthesized by A4GALT have important biological functions, including:

• Blood Group Antigens: A4GALT synthesizes glycosphingolipids containing the alpha-galactosyl residue, which serve as blood group antigens, such as the B antigen in the ABO blood group system.
• Cell Surface Recognition: Glycosphingolipids with alpha-galactosyl residues are involved in cell-cell recognition, adhesion, and interaction with pathogens, toxins, and immune cells.
• Tissue Development: A4GALT-mediated glycosphingolipid synthesis contributes to tissue development, differentiation, and maintenance, particularly in the nervous system and gastrointestinal tract.

Clinical Implications

Mutations or dysregulation of A4GALT gene expression or enzymatic activity can lead to alterations in glycosphingolipid composition and structure, which may have clinical implications. Deficiencies or abnormalities in glycosphingolipids synthesized by A4GALT have been associated with certain diseases, including certain types of kidney disease, gastrointestinal disorders, and immune-related conditions.