Beta-galactoside alpha-2,6-sialyltransferase 1 (ST6GAL1) (ST6GAL1)

Beta-galactoside alpha-2,6-sialyltransferase 1 (ST6GAL1), also known as CD75, is a Golgi-resident type II membrane protein that functions as a glycosyltransferase. It catalyzes the transfer of sialic acid from CMP-sialic acid to the terminal galactose of N-glycans in an alpha-2,6 linkage, a modification that defines the CD75 carbohydrate epitope [UniProt P15907]. This enzyme is essential for the normal development and function of B-cells, and its absence leads to significant immune deficiencies in model organisms [NCBI Gene]. In oncology, ST6GAL1 is frequently overexpressed and is associated with poor prognosis, as it sialylates and modulates the activity of various cell surface receptors, including EGFR, HER2, and Fas, thereby promoting cell survival and metastasis [PubMed: 31484688]. Although no ST6GAL1-targeted therapies are currently FDA-approved, the enzyme is a target of interest for small-molecule inhibitors and glycan-modifying agents designed to disrupt oncogenic signaling and enhance the efficacy of chemotherapy [PubMed: 23956127]. Therapeutic development must carefully manage potential safety concerns related to the enzyme's broad role in systemic glycosylation and immune homeostasis.

Other names

CD75SIAT1ST6Gal-IAlpha 2,6-sialyltransferase 1B-cell antigen CD75

Competitive or non-competitive inhibition of the ST6GAL1 enzyme, preventing the addition of alpha-2,6-linked sialic acid to terminal glycans on glycoproteins and glycolipids [PubMed: 23956127].