Planned Member


Principal Investigator
Akihiro Harada
Department of Cell Biology, Graduate School of Medicine, Osaka University

Investigation of sorting zones during polarized transport in epithelial cells

Research abstract

Cell polarity depends on intracellular polarized transport. We previously observed that different apical proteins accumulated at distinct sites in mice deficient in the small GTPase Rab8. Previously, another principal investigator in this research grant, Dr. Gotoh, observed that different proteins localized at distinct Golgi apparatus in flies. Thus, in this research project, we would like to observe that different molecules (GPI-anchor proteins, glycoproteins, etc.) go through distinct zones on their way to the plasma membrane using the gene knockin and super-resolution microscope / electron microscope in collaboration with co-investigators Drs. Nishino and Kinoshita.
The main projects of our team are shown below.

(1) Observe whether glycosylation enzymes or GPI synthases localize to restricted areas (zones) of the Golgi apparatus

(2) Observe whether the zones change in mice incapable of apical transport, such as Rab8 knockout mice

(3) Identify proteins constituting the zones using BioID or other techniques to determine what proteins constitute the sorting zones

Original papers

  1. Sato, T., Mushiake, S., Kato, Y., Sato, K., Sato, M., Takeda, N., Ozono, K., Miki, K., Kubo, Y., Tsuji, A., Harada, R., and Harada, A. (2007) The Rab8 GTPase regulates apical protein localization in intestinal cells. Nature 448, 366-369
  2. Yamamoto, K., Sato, T., Matsui, T., Sato, M., Okada, T., Yoshida, H., Harada, A., and Mori, K. Transcriptional induction of mammalian ER quality control proteins is mediated by single or combined action of ATF6α and XBP1 Dev Cell 13, 365-376
  3. D’Angelo, G., Uemura, T., Chuang, C-C., Polishchuk, E., Santoro, M., Ohvo-Rekila, H., Sato, T., Di Tullio, G., Varriale, A., D’Auria, S., Daniele, T., Capuani, F., Johannes, L., Mattjus, P., Monti, M., Pucci, P., Williams, RL., Burke, JE., Platt, FM., Harada, A., and De Matteis, MA. (2013) Vesicular and non-vesicular transport feed distinct glycosylation pathways in the Golgi. Nature 501, 116-120
  4. Nakajo, A., Yoshimura, SI., Togawa, H., Kunii, M., Iwano, T., Izumi, A., Noguchi, Y., Watanabe, A., Goto, A., Sato, T., and Harada, A. (2016) EHBP1L1 coordinates Rab8 and Bin1 to regulate apical-directed transport in polarized epithelial cells. J Cell Biol 212, 297-306
  5. Ishikawa, T., Toyama, T., Nakamura, Y., Tamada, K., Shimizu, H., Ninagawa, S., Okada, T., Kamei, Y., Ishikawa-Fujiwara, T., Todo, T., Aoyama, E., Takigawa, M., Harada, A., and Mori, K. (2017) UPR transducer BBF2H7 allows export of type II collagen in a cargo-and developmental stage–specific manner J Cell Biol. 216, 1761-1774