フルテキストURL elife_7_30246.pdf
著者 Takeda, Tetsuya| Kozai, Toshiya| Yang, Huiran| Ishikuro, Daiki| Seyama, Kaho| Kumagai, Yusuke| Abe, Tadashi| Yamada, Hiroshi| Uchihashi, Takayuki| Ando, Toshio| Takei, Kohji|
抄録 Dynamin is a mechanochemical GTPase essential for membrane fission during clathrin-mediated endocytosis. Dynamin forms helical complexes at the neck of clathrin-coated pits and their structural changes coupled with GTP hydrolysis drive membrane fission. Dynamin and its binding protein amphiphysin cooperatively regulate membrane remodeling during the fission, but its precise mechanism remains elusive. In this study, we analyzed structural changes of dynamin-amphiphysin complexes during the membrane fission using electron microscopy (EM) and high-speed atomic force microscopy (HS-AFM). Interestingly, HS-AFM analyses show that the dynamin-amphiphysin helices are rearranged to form clusters upon GTP hydrolysis and membrane constriction occurs at protein-uncoated regions flanking the clusters. We also show a novel function of amphiphysin in size control of the clusters to enhance biogenesis of endocytic vesicles. Our approaches using combination of EM and HS-AFM clearly demonstrate new mechanistic insights into the dynamics of dynamin-amphiphysin complexes during membrane fission.
キーワード EM HS-AFM amphiphysin biophysics cell biology dynamin human in vitro reconstitution membrane remodeling structural biology
発行日 2018-01
出版物タイトル eLife
7巻
出版者 eLife Sciences Publications
開始ページ e30246
ISSN 2050-084X
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
論文のバージョン publisher
PubMed ID 29357276
DOI 10.7554/eLife.30246
Web of Sience KeyUT 000423036500001
関連URL isVersionOf https://doi.org/10.7554/eLife.30246
フルテキストURL elife_7_35122.pdf elife_7_35122_fig.pdf
著者 Hamada, Mayuko| Schröder, Katja| Bathia, Jay| Kürn, Ulrich| Fraune, Sebastian| Khalturina, Mariia| Khalturin, Konstantin| Shinzato, Chuya| Satoh, Nori| Bosch, Thomas CG|
抄録 Many multicellular organisms rely on symbiotic associations for support of metabolic activity, protection, or energy. Understanding the mechanisms involved in controlling such interactions remains a major challenge. In an unbiased approach we identified key players that control the symbiosis between Hydra viridissima and its photosynthetic symbiont Chlorella sp. A99. We discovered significant up-regulation of Hydra genes encoding a phosphate transporter and glutamine synthetase suggesting regulated nutrition supply between host and symbionts. Interestingly, supplementing the medium with glutamine temporarily supports in vitro growth of the otherwise obligate symbiotic Chlorella, indicating loss of autonomy and dependence on the host. Genome sequencing of Chlorella sp. A99 revealed a large number of amino acid transporters and a degenerated nitrate assimilation pathway, presumably as consequence of the adaptation to the host environment. Our observations portray ancient symbiotic interactions as a codependent partnership in which exchange of nutrients appears to be the primary driving force.
キーワード Chlorella Hydra evolutionary biology genome nitrogen metabolism symbiosis
発行日 2018-03-31
出版物タイトル eLife
7巻
出版者 eLife Sciences Publications
開始ページ e35122
ISSN 2050-084X
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
論文のバージョン publisher
PubMed ID 29848439
DOI 10.7554/eLife.35122
Web of Sience KeyUT 000436227400001
関連URL isVersionOf https://doi.org/10.7554/eLife.35122