UPR transducer BBF2H7 allows export of type II collagen in a cargo- and developmental stage- specific manner

Tokiro Ishikawa, Takuya Toyama, Yuki Nakamura, Kentaro Tamada, Hitomi Shimizu, Satoshi Ninagawa, Tetsuya Okada, Yasuhiro Kamei, Tomoko Ishikawa-Fujiwara, Takeshi Todo, Eriko Aoyama, Masaharu Takigawa, Akihiro Harada, Kazutoshi Mori

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18 Citations (Scopus)


The unfolded protein response (UPR) handles unfolded/misfolded proteins accumulated in the endoplasmic reticulum (ER). However, it is unclear how vertebrates correctly use the total of ten UPR transducers. We have found that ER stress occurs physiologically during early embryonic development in medaka fish and that the smooth alignment of notochord cells requires ATF6 as a UPR transducer, which induces ER chaperones for folding of type VIII (short-chain) collagen. After secretion of hedgehog for tissue patterning, notochord cells differentiate into sheath cells, which synthesize type II collagen. In this study, we show that this vacuolization step requires both ATF6 and BBF2H7 as UPR transducers and that BBF2H7 regulates a complete set of genes (Sec23/24/13/31, Tango1, Sedlin, and KLHL12) essential for the enlargement of COP II vesicles to accommodate long-chain collagen for export, leading to the formation of the perinotochordal basement membrane. Thus, the most appropriate UPR transducer is activated to cope with the differing physiological ER stresses of different content types depending on developmental stage.

Original languageEnglish
Pages (from-to)1761-1774
Number of pages14
JournalJournal of Cell Biology
Issue number6
Publication statusPublished - Jun 1 2017


ASJC Scopus subject areas

  • Cell Biology

Cite this

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., & Mori, K. (2017). UPR transducer BBF2H7 allows export of type II collagen in a cargo- and developmental stage- specific manner. Journal of Cell Biology, 216(6), 1761-1774. https://doi.org/10.1083/jcb.201609100