In the cells, there exist numerous nano-scale structures called organelles. Each organelle possesses its own space and highly differenciated functions in the cells. These organelles build up a huge network similar to a city, by connecting each other using membrane traffic system. We are studying the mechanisms of the organelle formation and the membrane traffic.
1. Development of electronmicroscopy. For the purpose to analyze cells and tissues in nano-scale resolution, we developed and applied the techniques for electron microscopy, including immuno-electron microscopy, three dimensional analysis by electron tomography, and correlative light and electron microscopy.
2. Clarification of autophagy. Autophagy is a process that degrades cytoplasmic constituents and has diverse physiological functions, including starvation adaptation,intracellular protein and organelle clearance, development,immunity, tumour suppression and cell death. We found 1. autophagosomal membrane is derived from endoplasmic reticulum (ER) by electron tomography, 2. autophagy promotes HIV infection, 3. autophagy is involved in acute pancreatitis, 4. autophagy is required for early development of mammalian embryos, 5. autophagy prevents neurodegenerative disease, 6. autophagy is indispensable to survive the early neonatal starvation period. 7. autophagy defends cells against invading bacteria.
