ジャーナル: Sci Rep / 年: 2019 タイトル: Cryo-Electron Tomography and Proteomics studies of centrosomes from differentiated quiescent thymocytes. 著者: Johan Busselez / Francisco Javier Chichón / Maria Josefa Rodríguez / Adan Alpízar / Séverine Isabelle Gharbi / Mònica Franch / Roberto Melero / Alberto Paradela / José L Carrascosa / José-Maria Carazo / 要旨: We have used cryo Electron Tomography, proteomics and immunolabeling to study centrosomes isolated from the young lamb thymus, an efficient source of quiescent differentiated cells. We compared the ...We have used cryo Electron Tomography, proteomics and immunolabeling to study centrosomes isolated from the young lamb thymus, an efficient source of quiescent differentiated cells. We compared the proteome of thymocyte centrosomes to data published for KE37 cells, focusing on proteins associated with centriole disengagement and centrosome separation. The data obtained enhances our understanding of the protein system joining the centrioles, a system comprised of a branched network of fibers linked to an apparently amorphous density that was partially characterized here. A number of proteins were localized to the amorphous density by immunolabeling (C-NAP1, cohesin SMC1, condensin SMC4 and NCAPD2), yet not DNA. In conjuction, these data not only extend our understanding of centrosomes but they will help refine the model that focus on the protein system associated with the centriolar junction.
全体 : Centrosome enriched from young lamb thymocytes
全体
名称: Centrosome enriched from young lamb thymocytes
要素
細胞器官・細胞要素: Centrosome enriched from young lamb thymocytes
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超分子 #1: Centrosome enriched from young lamb thymocytes
超分子
名称: Centrosome enriched from young lamb thymocytes / タイプ: organelle_or_cellular_component / ID: 1 / 親要素: 0 詳細: The centrosome were extracted accordingly to Komesli et al. 1989
由来(天然)
生物種: Ovis aries (ヒツジ) / 器官: Thymus / 組織: Thymus Lobules / Organelle: Centrosome / 細胞中の位置: cytoplasm near the nucleus
The sample was enriched by two step of sedimentation in sucrose gradient. The sucrose was washed out in several drops of buffer, the last of which included fiducial markers (10 nm bovine serum albumin (BSA)-coated gold beads) for tilt series alignment
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電子顕微鏡法
顕微鏡
FEI TITAN KRIOS
特殊光学系
エネルギーフィルター - 名称: Gatan 968 Quantum エネルギーフィルター - エネルギー下限: -10 eV エネルギーフィルター - エネルギー上限: 10 eV
Tilt series were aligned based on fiducials with IMOD and mass normalized using PRIISM. The ctf correction was processed on tilt series using TomoCTF. Tomogram were reconstructed using SIRT algorithm with TOMO3D. The number of frames per image were variable, with 8 frames at full tilt, through to 4 frames at zero tilt.
最終 再構成
使用したクラス数: 2 / アルゴリズム: FOURIER SPACE / 解像度のタイプ: BY AUTHOR / 解像度: 47.0 Å / 解像度の算出法: FSC 0.5 CUT-OFF / ソフトウェア - 名称: Dynamo (ver. 1.1.22) / 使用したサブトモグラム数: 282
抽出
トモグラム数: 4 / 使用した粒子像数: 800 / 手法: volume picked interactively / ソフトウェア - 名称: Dynamo (ver. 1.1.22) 詳細: Coarse models of the centriole microtubules were obtained using Fiber Tracing in Amira and converted for import in dynamo. From those coarse models, "filament with torsion" models were traced ...詳細: Coarse models of the centriole microtubules were obtained using Fiber Tracing in Amira and converted for import in dynamo. From those coarse models, "filament with torsion" models were traced in dynamo. The triplets were segregated from the doublets and triplets volume particle were windowed with overlap every 8.3nm along the "filament with torsion" models
CTF補正
ソフトウェア - 名称: TOMOCTF / 詳細: wiener filtering, made on tilt series
最終 3次元分類
クラス数: 4 / ソフトウェア - 名称: Dynamo (ver. 1.1.22) / 詳細: classification by PCA + k-means
最終 角度割当
タイプ: OTHER / ソフトウェア - 名称: Dynamo (ver. 1.1.22) 詳細: The particular geometry of the centriole with its repeat every 8.3nm along the proximal-distal axis and its coarse 9 fold symmetry was used to construct from each tomogram a model lowly ...詳細: The particular geometry of the centriole with its repeat every 8.3nm along the proximal-distal axis and its coarse 9 fold symmetry was used to construct from each tomogram a model lowly affected by missing wedge. Those coarse models were volume aligned and an initial reference were averaged from all the subtomogram particle using the coarse orientation of the particles determined that way. This model was iteratively refined. The reference model for the next iteration was made using 70% of the particles based on the best correlation during the alignment. For the finer step of refinement, a mask was used to restrict the alignment to an area covering 3 of the 8.3nm repeats.