Current research

We have access to the RIKEN Yokohama Cryo-EM facility, where an Aquilos 2 cryo-FIB/SEM and a Krios G4 cryo-TEM are available. Using these instruments, we perform cryo-electron tomography (cryo-ET), primarily on cultured mammalian cells, to address the following biological questions:

1. Molecular basis of nuclear envelope deformation Under specific cellular conditions, the nuclear envelope dynamically changes its shape. This nuclear envelope deformation is likely driven and regulated by surrounding cellular structures, such as chromatin, the nuclear lamina, and the cytoskeleton, but its molecular basis remains poorly understood. By visualizing deformed nuclear envelope using cryo-ET and analyzing the surrounding cellular architectures in situ, we aim to elucidate how molecules around the nuclear envelope reshape the nucleus.

2. Molecular basis of membrane vesicle formation In eukaryotic cells, proteins destined for the extracellular space or the plasma membrane are transported via vesicular trafficking. Membrane vesicle formation at cellular organelles involves coordinated processes, including coat protein assembly on membranes, selective cargo recognition, and membrane deformation. By analyzing the structure and spatial organization of coat proteins on membranes using cryo-ET, we aim to understand the molecular mechanisms underlying vesicle formation and its regulation from a structural perspective.

3. Expanding cryo-ET to diverse biological samples Recent technological advances have enabled us to perform cryo-ET analyses of large and complex samples, including tissues and whole organisms. By optimizing sample freezing and cryo-FIB/SEM milling procedures, we aim to extend our research to tissue-derived samples.