ABSTRACT
OBJECTIVE To investigate how MLKL functions on the membrane and explore its electrophysiological characters and structure. METHODS The full-length human MLKL were expressed in SF21 cells and purified using glutathione-sepharose affinity chromatography. The currents of purified MLKL proteins were recorded in avoltage-clamp mode using a Warner BC-535 bilayer clamp amplifier. The currents were digitized using pCLAMP 10.2 software. HEK293 cells were cultured and transfected with MLKL plasmid. Cell viability was examined using the CellTiter- Glo Luminescent Cell Viability Assay kit. RESULT MLKL forms cation channels that are permeable preferentially to Mg2+ rather than Ca2+ in the presence of Na+ and K+. Moreover,each MLKL monomer contains five transmembrane helices:H1, H2, H3 , H5 and H6 of the N-terminal domain which is sufficient to form channels. Finally, MLKL-induced membrane depolarization and cell death exhibit a positive correlation to its channel activity.