The nascent polypeptide possesses a cleavage site after the N-terminal signal sequence helix, rendering a mature MagT1 protein with four transmembrane helices.
Morpholino knockdown of MagT1 and TUSC3 protein expression in zebrafish embryos resulted in early developmental arrest; excess Mg2+ or supplementation with mammalian mRNAs rescued these effects.
[4] The reaction catalyzed by MagT1, or a potential downstream glycosylation target (e.g. a Mg2+ transporter), is: The identification of genetic changes and their functional consequences in patients with immunodeficiency resulting from loss of MAGT1 revealed that magnesium and MagT1 are key molecular players for T cell-mediated immune responses.
[5] This led to the description of XMEN (X-linked immunodeficiency with magnesium defect, Epstein-Barr Virus infection, and neoplasia) syndrome,[6] for which Mg2+ supplementation has been shown to be beneficial.
[7] Similarly, the identification of copy-number variation leading to dysfunctional MAGT1 in a family with atypical ATR-X syndrome and skin abnormalities, suggested that the MAGT1 defect is responsible for the cutaneous problems.