ジャーナル: Nat Commun / 年: 2022 タイトル: SepN is a septal junction component required for gated cell-cell communication in the filamentous cyanobacterium Nostoc. 著者: Ann-Katrin Kieninger / Piotr Tokarz / Ana Janović / Martin Pilhofer / Gregor L Weiss / Iris Maldener / 要旨: Multicellular organisms require controlled intercellular communication for their survival. Strains of the filamentous cyanobacterium Nostoc regulate cell-cell communication between sister cells via a ...Multicellular organisms require controlled intercellular communication for their survival. Strains of the filamentous cyanobacterium Nostoc regulate cell-cell communication between sister cells via a conformational change in septal junctions. These multi-protein cell junctions consist of a septum spanning tube with a membrane-embedded plug at both ends, and a cap covering the plug on the cytoplasmic side. The identities of septal junction components are unknown, with exception of the protein FraD. Here, we identify and characterize a FraD-interacting protein, SepN, as the second component of septal junctions in Nostoc. We use cryo-electron tomography of cryo-focused ion beam-thinned cyanobacterial filaments to show that septal junctions in a sepN mutant lack a plug module and display an aberrant cap. The sepN mutant exhibits highly reduced cell-cell communication rates, as shown by fluorescence recovery after photobleaching experiments. Furthermore, the mutant is unable to gate molecule exchange through septal junctions and displays reduced filament survival after stress. Our data demonstrate the importance of controlling molecular diffusion between cells to ensure the survival of a multicellular organism.
ダウンロード / ファイル: emd_16061.map.gz / 形式: CCP4 / 大きさ: 348.8 MB / タイプ: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
ボクセルのサイズ
X=Y=Z: 13.52 Å
密度
最小 - 最大
-90.3553 - 52.999397000000002
平均 (標準偏差)
-0.000000000037036 (±9.044881)
対称性
空間群: 1
詳細
EMDB XML:
マップ形状
Axis order
X
Y
Z
Origin
0
0
0
サイズ
1440
1024
62
Spacing
1024
1440
62
セル
A: 13844.48 Å / B: 19468.8 Å / C: 838.24005 Å α=β=γ: 90.0 °
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添付データ
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試料の構成要素
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全体 : The septal region from FIB milled filament of Nostoc sp. PCC 7120...
全体
名称: The septal region from FIB milled filament of Nostoc sp. PCC 7120 sepN-mbp-sfgfp mutant
要素
複合体: The septal region from FIB milled filament of Nostoc sp. PCC 7120 sepN-mbp-sfgfp mutant
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超分子 #1: The septal region from FIB milled filament of Nostoc sp. PCC 7120...
超分子
名称: The septal region from FIB milled filament of Nostoc sp. PCC 7120 sepN-mbp-sfgfp mutant タイプ: complex / ID: 1 / 親要素: 0
由来(天然)
生物種: Nostoc sp. PCC 7120 = FACHB-418 (バクテリア)
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実験情報
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構造解析
手法
クライオ電子顕微鏡法
解析
電子線トモグラフィー法
試料の集合状態
cell
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試料調製
緩衝液
pH: 7.4 / 詳細: BG11 broth
凍結
凍結剤: ETHANE-PROPANE / チャンバー内湿度: 100 % / チャンバー内温度: 298.15 K / 装置: FEI VITROBOT MARK IV
詳細
Thin lamellae through plunge-frozen Nostoc filaments
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: 3 / 集束イオンビーム - 電流: 0.058 / 集束イオンビーム - 時間: 1500 / 集束イオンビーム - 温度: 123 K / 集束イオンビーム - Initial thickness: 3000 / 集束イオンビーム - 最終 厚さ: 200 集束イオンビーム - 詳細: The value given for _em_focused_ion_beam.instrument is Zeiss Crossbeam 550. This is not in a list of allowed values {'DB235', 'OTHER'} so OTHER is written into the XML file.