ジャーナル: Elife / 年: 2025 タイトル: Molecular architecture of thylakoid membranes within intact spinach chloroplasts. 著者: Wojciech Wietrzynski / Lorenz Lamm / William H J Wood / Matina-Jasemi Loukeri / Lorna Malone / Tingying Peng / Matthew P Johnson / Benjamin D Engel / 要旨: Thylakoid membranes coordinate the light reactions of photosynthesis across multiple scales, coupling the architecture of an elaborate membrane network to the spatial organization of individual ...Thylakoid membranes coordinate the light reactions of photosynthesis across multiple scales, coupling the architecture of an elaborate membrane network to the spatial organization of individual protein complexes embedded within this network. Previously, we used in situ cryo-electron tomography (cryo-ET) to reveal the native thylakoid architecture of the green alga (Engel et al., 2015) and then map the molecular organization of these thylakoids with single-molecule precision (Wietrzynski et al., 2020). However, it remains to be shown how generalizable this green algal blueprint is to the thylakoids of vascular plants, which possess distinct membrane architecture subdivided into grana stacks interconnected by non-stacked stromal lamellae. Here, we continue our cryo-ET investigation to reveal the molecular architecture of thylakoids within intact chloroplasts isolated from spinach (). We visualize the fine ultrastructural details of grana membranes, as well as interactions between thylakoids and plastoglobules. We apply AI-based computational approaches (Lamm et al., 2024) to quantify the organization of photosynthetic complexes within the plane of the thylakoid membrane and across adjacent stacked membranes. Our analysis reveals that the molecular organization of thylakoid membranes in vascular plants and green algae is strikingly similar. We find that PSII organization is non-crystalline and has uniform concentration both within the membrane plane and across stacked grana membranes. Similar to , we observe strict lateral heterogeneity of PSII and PSI at the boundary between appressed and non-appressed thylakoid domains, with no evidence for a distinct grana margin region where these complexes have been proposed to intermix. Based on these measurements, we support a simple two-domain model for the molecular organization of thylakoid membranes in both green algae and plants.
凍結剤: ETHANE-PROPANE / チャンバー内湿度: 75 % / チャンバー内温度: 295 K / 装置: FEI VITROBOT MARK IV
Cryo protectant
no cryoprotectant
切片作成
集束イオンビーム - 装置: OTHER / 集束イオンビーム - イオン: OTHER / 集束イオンビーム - 電圧: 30 / 集束イオンビーム - 電流: 0.1 / 集束イオンビーム - 時間: 1800 / 集束イオンビーム - 温度: 77 K / 集束イオンビーム - Initial thickness: 1000 / 集束イオンビーム - 最終 厚さ: 120 集束イオンビーム - 詳細: Clumps of chloroplast were milled in a step-wise manner according to the routine protocols.. The value given for _em_focused_ion_beam.instrument is TFS Aquilos. ...集束イオンビーム - 詳細: Clumps of chloroplast were milled in a step-wise manner according to the routine protocols.. The value given for _em_focused_ion_beam.instrument is TFS Aquilos. This is not in a list of allowed values {'OTHER', 'DB235'} so OTHER is written into the XML file.