Structural Biology Of Human Magnesium Channel TRPM6

Magnesium ion is the second most abundant cation in the biological system and plays a critical role in human life.However,the regulation and transport of magnesium in the human body are not well understood.Transient receptor potential cation channel subfamily M member 6（TRPM6）is one of the few magnesium ion channels in the biological system and plays a crucial role in maintaining the homeostasis and regulation of magnesium ions.TRPM6 belongs to the transient receptor potential cation channel M subfamily（TRPM）family,and abnormalities in TRPM channel expression and function may lead to various diseases,including cardiovascular diseases,neurodegenerative diseases,and organ dysfunction.TRPM family members have become a new type of target for disease diagnosis,treatment,and drug design.TRPM6is highly expressed in the intestine and kidney,has high permeability to Mg²⁺,and plays a crucial role in maintaining magnesium homeostasis in the human body.TRPM6 is closely associated to various diseases,and mutations or deletions in the TRPM6 gene can lead to a decrease in Mg²⁺transport levels,resulting in hypomagnesemia and a series of complications such as hypocalcemia,type 2 diabetes,and epilepsy.Currently,the structure of TRPM6 has not been resolved.In this study,different TRPM6 clone vectors were generated using molecular cloning technology,and protein N and C-terminal truncations,fusion protein tags,and amino acid mutations were screened using mammalian expression systems and affinity chromatography technology to optimize the conditions for protein expression and purification.A highly pure and stable TRPM6 protein was successfully obtained.Meanwhile,the TRPM6protein was reconstituted into nanodiscs using the membrane scaffold protein 2N2 and lipids,which improved its stability and uniformity and provided the possibility of obtaining a high-resolution three-dimensional structure of TRPM6.The resolution of the TRPM6 structure will elucidate its regulatory mechanism at the molecular level,understand its pathogenesis,and provide a structural basis for the development of small-molecule drugs targeting TRPM6.