B3GALNT1 Gene - Function, Mutations, and Associated Diseases | NCBI, UniProt, OMIM

B3GALNT1 encodes beta-1,3-N-acetylgalactosaminyltransferase 1, a Golgi enzyme that catalyzes the transfer of N-acetylgalactosamine (GalNAc) to globotriaosylceramide (Gb3) to form globoside (Gb4), a key step in globo-series glycosphingolipid biosynthesis. The enzyme is essential for the synthesis of P blood group antigens and plays roles in cell adhesion, signaling, and cancer progression. Mutations in B3GALNT1 cause autosomal recessive hereditary spastic paraplegia type 26 (SPG26).

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Glycosphingolipid biosynthesis - globo series (KEGG: hsa00603)

• Metabolism of glycosphingolipids (Reactome: R-HSA-1660661)

B3GALNT1 is a type II transmembrane glycoprotein localized to the Golgi apparatus. It contains a short N-terminal cytoplasmic tail, a transmembrane domain, and a large C-terminal catalytic domain facing the Golgi lumen. The enzyme specifically transfers GalNAc from UDP-GalNAc to Gb3 (globotriaosylceramide) to form Gb4 (globoside). This reaction is critical for the biosynthesis of globo-series glycosphingolipids, which are components of cell membranes involved in cell-cell recognition, adhesion, and signaling. Loss of function leads to accumulation of Gb3 and deficiency of Gb4, causing neurological degeneration in SPG26. In cancer, altered expression of B3GALNT1 modulates tumor cell glycosylation, impacting metastasis and immune evasion.