MAGT1 Gene

The MAGT1 gene (MAGT1 stands for "magnesium transporter1") is a protein-coding gene localized to chromosome Xq21.1.

The MAGT1 gene encodes a ubiquitously expressed magnesium cation transporter protein localized to the cell membrane. MAGT1 functions as a subunit of the oligosaccharyltransferase (OST) complex and in particular the STT3B complex (Blommaert E et al. 2019) and therefore plays a role in N-glycosylation. This gene may have multiple in-frame translation initiation sites, one of which encodes a shorter protein with an N-terminus containing a signal peptide at amino acids 1-29.

Diseases associated with MAGT1 include.

• Immunodeficiency, X-linked with magnesium defect, Epstein-Barr virus infection and neoplasia and congenital glycosylation disorder (XMEN).
• XLID, a form of X-linked intellectual disability (Blommaert E et al. 2019) .

Magnesium transporter 1, encoded by this gene, is likely involved in N-glycosylation of diverse substrates. Specifically, it is required for glycosylation of a subset of acceptor sites located near cysteine residues; appears to act redundantly to TUSC3 in this function. Furthermore, the protein is involved in Mg(2+) transport in epithelial cells.

1. Ramírez AS et al. (2019) Cryo-electron microscopy structures of human oligosaccharyltransferase complexes OST-A and OST-B. Science 366:1372-1375.
2. Ravell JC et al (2020) An Update on XMEN Disease. J Clin Immunol 40: 671-681.