Genetically Encoded Tools to Monitor and Interrogate Membrane Contact Sites

Membrane contact sites (MCSs) are dynamic subcellular compartments formed between organelles that coordinate diverse aspects of cellular communication, including signaling, metabolism, and membrane organization. Tools capable of monitoring and controlling the spatially localized and dynamic properties of MCSs are needed to dissect their regulatory mechanisms and physiological roles. Recent advances in protein engineering have begun to address this need. Proximity-based reporters, chemogenetic approaches, and optogenetic systems have been developed to enable the visualization, interrogation, and manipulation of inter-organelle contacts with improved spatial and temporal precision. This minireview highlights key developments in these molecular toolkits and their representative applications in studying MCS biology. These approaches provide new insights into organelle crosstalk and may inform future therapeutic strategies targeting MCSs.