MAGT1, short for magnesium transporter 1, is a subunit of the oligosaccharide protein complex with thiol-disulfide oxidoreductase activity, crucial for N-glycosylation process. It is also involved in magnesium homeostasis, which is essential for numerous cellular functions, and has been linked to signaling in T lymphocytes [1,3,4].

In Magt1-deficient mice (Magt1-/y), accelerated occlusive arterial thrombus formation, shortened bleeding time, and severe brain damage upon focal cerebral ischemia were observed. These defects were due to increased calcium influx and enhanced mediator release, which strengthened platelet reactivity. Supplementation of MgCl2 or blocking TRPC6 channels normalized platelet aggregation. In addition, MAGT1-deficient human platelets showed hyperaggregation. Haploinsufficiency of TRPC6 in Magt1-/y mice could normalize GPVI signaling, platelet aggregation, and thrombus formation, suggesting a functional link between MAGT1 and TRPC6 [1]. In X-linked immunodeficiency with magnesium defect (XMEN) patients, MAGT1 deficiency led to severe platelet dysfunction and impaired N-glycosylation of platelet glycoproteins. Platelet aggregation, integrin activation, calcium mobilization, and protein kinase C activity were impaired, but were corrected after hematopoietic stem cell transplantation [2].

In conclusion, MAGT1 is essential for normal platelet function and N-glycosylation, as well as for maintaining cation homeostasis. The study of Magt1-deficient mouse models has revealed its significant role in arterial thrombosis and stroke, as well as in XMEN-associated platelet dysfunction. Understanding MAGT1 function provides insights into the mechanisms underlying these disease conditions, potentially leading to new therapeutic strategies [1,2].

References:

1. Gotru, Sanjeev Kiran, Mammadova-Bach, Elmina, Sogkas, Georgios, Gudermann, Thomas, Braun, Attila. 2023. MAGT1 Deficiency Dysregulates Platelet Cation Homeostasis and Accelerates Arterial Thrombosis and Ischemic Stroke in Mice. In Arteriosclerosis, thrombosis, and vascular biology, 43, 1494-1509. doi:10.1161/ATVBAHA.122.318115. https://pubmed.ncbi.nlm.nih.gov/37381987/

2. Kauskot, Alexandre, Mallebranche, Coralie, Bruneel, Arnaud, Miot, Charline, Adam, Frédéric. 2023. MAGT1 deficiency in XMEN disease is associated with severe platelet dysfunction and impaired platelet glycoprotein N-glycosylation. In Journal of thrombosis and haemostasis : JTH, 21, 3268-3278. doi:10.1016/j.jtha.2023.05.007. https://pubmed.ncbi.nlm.nih.gov/37207862/

3. Trapani, Valentina, Shomer, Naomi, Rajcan-Separovic, Evica. . The role of MAGT1 in genetic syndromes. In Magnesium research, 28, 46-55. doi:. https://pubmed.ncbi.nlm.nih.gov/26422833/

4. Wolf, Federica I, Trapani, Valentina. . MagT1: a highly specific magnesium channel with important roles beyond cellular magnesium homeostasis. In Magnesium research, 24, S86-91. doi:10.1684/mrh.2011.0288. https://pubmed.ncbi.nlm.nih.gov/21947671/