Significance of polarized transport zones in organelles during polarized transport in epithelial cells

2022 Fiscal Year Final Research Report

• Project Area: Toward an integrative understanding of functional zones in organelles
• Project/Area Number: 17H06422
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Biological Sciences
• Research Institution: Osaka University
• Principal Investigator: Harada Akihiro 大阪大学, 大学院医学系研究科, 教授 (40251441)
• Co-Investigator(Kenkyū-buntansha): 木下 タロウ 大阪大学, 微生物病研究所, 特任教授(常勤) (10153165) ; 西野 美都子 大阪大学, 産業科学研究所, 准教授 (30510440)
• Project Period (FY): 2017-06-30 – 2022-03-31
• Keywords: ゴルジ体 / 糖鎖合成酵素 / ゾーン

Outline of Final Research Achievements

Various tags were introduced into the glycosylation enzymes localized in the Golgi complex in mammalian cell lines by gene knock-in method. After immunostaining, the localization and area of the sorting transport zone were identified using super-resolution microscopy and electron microscopy. Model proteins of glycoproteins were expressed and observed to pass specifically through the sorting zone where they were modified. Since it was suggested that different glycosylation enzymes occupy different sites ('zones') in the Golgi, the molecular mechanism of these glycosyltransferases to form such zones was investigated. We knocked in biotinylation enzymes (APEX, BioID, etc.) to identify biotinylated molecules and found a number of specifically biotinylated molecules.

Free Research Field

生物系

Academic Significance and Societal Importance of the Research Achievements

ゴルジ体の1つの槽の中で、異なる種類の糖鎖を伸長させる糖鎖合成酵素が混ざり合っているのか、独立に局在するのかについてはこれまで殆ど知られておらず、それが糖鎖研究や細胞生物学研究の大きな障害になっていた。本研究によって糖鎖合成酵素の局在が判明し、それらのゴルジ体内の動きが解明されたこと、それのみならずゴルジ体の基本的な構築についての知見が得られたことは、本分野の前進に向けて大きな学術的意義を持つ。更にゴルジ体の構造蛋白質の異常による疾患が多数知られているが、それらの発症の分子機構は全く不明である。その病因の解明にも本研究が大きく寄与できると考えている。