The environment in the ECM is harsher than that in the cell, and the component proteins have a very specific three-dimensional structure. For this reason, live imaging with fluorescent proteins has rarely been performed, and the development of ECM-specific imaging technology is essential for the advancement of ECM dynamics research in this field. In this study, we will use two types of collagen, which have been successfully live-imaged by the research members, as a stepping stone to clarify problems that occur during intracellular trafficking and secretion processes when imaging ECM-constituent proteins. We will then develop a technical platform to visualize various ECM- constituent proteins to promote live imaging in this Transformative Research Areas. In addition, to visualize not only the dynamics of protein molecules themselves but also the functional dynamics within the ECM, we will develop fluorescent dyes to visualize protein-protein interactions in the ECM by fluorescence lifetime imaging and sensors to measure mechanical properties in the ECM. In addition, we will develop a designer matrix that can change its elastic modulus using a photoreceptor protein that can change its aggregation state upon light stimulation, and establish an experimental basis for observing the effects of manipulation of the ECM.

Knock-in mice and human iPS cells expressing the developed probes will be sequentially established in the RIKEN BioResource Research Center of the research members and provided as in vivo research resources to researchers in the field and at home and abroad.