The endoplasmic reticulum (ER) serves as the major intracellular calcium store. The release of calcium from this store regulates a variety of cellular functions, hence playing a key role in regulating apoptosis. The transmembrane BAX inhibitor-1 motif-containing 6 (TMBIM6) is an evolutionarily conserved multifunctional ER membrane protein that mediates calcium homeostasis to protect against apoptosis and ER stress. We study a bacterial homolog of TMBIM6 and report several previously unidentified conformational substates involved in the calcium transport process. Our findings stimulate a model of calcium-release channel showing that membrane protein functioning requires the interconversion between distinct conformations in preexisting conformational equilibria.

PNAS, 117 (2020) 30126-30134

We use spin-nanodisc to improve SNR of DEER signals for conventional membrane protein study. The new approach enables a significant improvement in the distance resolution obtainable from the DEER result by Tikhonov method.

RSC Advances, 9 (2019) 9014-9021

Membrane proteins are incorporated in various environments, including detergent, membrane vesicles, and nanodisc. ESR distance measurements show that the protein behave differently with environments.