The molecular mechanisms of P-glycoprotein (P-gp; also known as MDR1 or ABCB1) have been mainly investigated using artificial membranes such as lipid-detergent mixed micelles, artificial lipid bilayers, and membrane vesicles derived from cultured cells. Although these in vitro experiments help illustrate details about the molecular mechanisms of P-gp, they do not reflect physiological membrane environments in terms of lateral pressure, curvature, constituent lipid species, etc. The protocol presented here includes a detailed guide for analyzing the conformational change of human P-gp in living HEK293 cells by using intramolecular fluorescence resonance energy transfer (FRET), in which excitation of the donor fluorophore is transferred to the acceptor without emission of a photon when two

Immune tolerance and response are both largely driven by the interactions between the major histocompatibility complex (MHC) expressed by antigen presenting cells (APCs), T-cell receptors (TCRs) on T-cells, and their cognate antigens. Disordered interactions cause the pathogenesis of autoimmune diseases such as type 1 diabetes. Therefore, the identification of antigenic epitopes of autoreactive T-cells leads to important advances in therapeutics and biomarkers. Next-generation sequencing methods allow for the rapid identification of thousands of TCR clonotypes from single T-cells, and thus there is a need to determine cognate antigens for identified TCRs. This protocol describes a reporter system of T-cell activation where the fluorescent reporter protein ZsGreen-1 is driven by nuclear