Natural Sciences and Engineering Research Council (NSERC, Canada)
2020-04241
カナダ
Other private
17868
カナダ
Canadian Institutes of Health Research (CIHR)
FDN-143228
カナダ
Natural Sciences and Engineering Research Council (NSERC, Canada)
RGPIN-2018-03951
カナダ
引用
ジャーナル: J Mol Biol / 年: 2021 タイトル: Biochemical Insight into Novel Rab-GEF Activity of the Mammalian TRAPPIII Complex. 著者: Noah J Harris / Meredith L Jenkins / Udit Dalwadi / Kaelin D Fleming / Sung-Eun Nam / Matthew A H Parson / Calvin K Yip / John E Burke / 要旨: Transport Protein Particle complexes (TRAPP) are evolutionarily conserved regulators of membrane trafficking, with this mediated by their guanine nucleotide exchange factor (GEF) activity towards Rab ...Transport Protein Particle complexes (TRAPP) are evolutionarily conserved regulators of membrane trafficking, with this mediated by their guanine nucleotide exchange factor (GEF) activity towards Rab GTPases. In metazoans evidence suggests that two different TRAPP complexes exist, TRAPPII and TRAPPIII. These two complexes share a common core of subunits, with complex specific subunits (TRAPPC9 and TRAPPC10 in TRAPPII and TRAPPC8, TRAPPC11, TRAPPC12, TRAPPC13 in TRAPPIII). TRAPPII and TRAPPIII have distinct specificity for GEF activity towards Rabs, with TRAPPIII acting on Rab1, and TRAPPII acting on Rab1 and Rab11. The molecular basis for how these complex specific subunits alter GEF activity towards Rab GTPases is unknown. Here we have used a combination of biochemical assays, hydrogen deuterium exchange mass spectrometry (HDX-MS) and electron microscopy to examine the regulation of TRAPPII and TRAPPIIII complexes in solution and on membranes. GEF assays revealed that TRAPPIII has GEF activity against Rab1 and Rab43, with no detectable activity against the other 18 Rabs tested. The TRAPPIII complex had significant differences in protein dynamics at the Rab binding site compared to TRAPPII, potentially indicating an important role of accessory subunits in altering the active site of TRAPP complexes. Both the TRAPPII and TRAPPIII complexes had enhanced GEF activity on lipid membranes, with HDX-MS revealing numerous conformational changes that accompany membrane association. HDX-MS also identified a membrane binding site in TRAPPC8. Collectively, our results provide insight into the functions of TRAPP complexes and how they can achieve Rab specificity.
全体 : Transport Protein Particle Complex III (TRAPP III)
全体
名称: Transport Protein Particle Complex III (TRAPP III)
要素
複合体: Transport Protein Particle Complex III (TRAPP III)
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超分子 #1: Transport Protein Particle Complex III (TRAPP III)
超分子
名称: Transport Protein Particle Complex III (TRAPP III) / タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: #1 / 詳細: Mammalian TRAPP III purified from Sf9 insect cells
由来(天然)
生物種: Homo sapiens (ヒト)
組換発現
生物種: Spodoptera frugiperda (ツマジロクサヨトウ)
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実験情報
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構造解析
手法
ネガティブ染色法
解析
単粒子再構成法
試料の集合状態
particle
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試料調製
濃度
0.02 mg/mL
緩衝液
pH: 7.5 構成要素:
濃度
名称
式
20.0 mM
HEPES
100.0 mM
Sodium Chloride
NaCl
0.5 mM
Tris(2-carboxyethyl)phosphine
詳細: Freshly prepared gel filtration buffer, filtered through 0.22um filter and degassed
染色
タイプ: NEGATIVE / 材質: Uranyl Formate 詳細: Negative stained EM samples prepared by adsorbing sample on grid for 15s, followed by blotting of sample, 2 washes with water, 1 wash with stain and a final 30s soak in stain.
TRAPP III Complex was purified to homogeneity using affinity chromatography followed by size exclusion chromatography. Samples were kept at 4 degrees and shipped on wet ice for single particle EM analysis.
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電子顕微鏡法
顕微鏡
TFS TALOS L120C
撮影
フィルム・検出器のモデル: FEI CETA (4k x 4k) / デジタル化 - サイズ - 横: 4096 pixel / デジタル化 - サイズ - 縦: 4096 pixel / デジタル化 - サンプリング間隔: 2.27 µm / 撮影したグリッド数: 1 / 実像数: 100 / 平均露光時間: 1.0 sec. / 平均電子線量: 5.0 e/Å2 詳細: Images were manually collected every 200nm on a grid square after a 30s delay for stage stabilization. Focus was calibrated every 10 images using thin rings in the power spectra.
試料ホルダーモデル: SIDE ENTRY, EUCENTRIC / ホルダー冷却材: NITROGEN
実験機器
モデル: Talos L120C / 画像提供: FEI Company
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画像解析
詳細
Images were first imported to RELION 3.1 for pre-processing and particle picking
粒子像選択
選択した数: 38213 詳細: 200 particles were manually picked and classified into 4 classes to generate a template. Templates were then used for automated picking using the RELION reference-based auto picker.
CTF補正
ソフトウェア - 名称: CTFFIND (ver. 4.1) 詳細: CTF estimation was carried out using all default settings in CTFFIND4, CTF correction carried out during 2D and 3D classification
初期モデル
モデルのタイプ: NONE 詳細: Ab initio reconstruction using cryoSPARC v2.14 ab initio reconstruction job set to generate 2 classes
クラス数: 2 / ソフトウェア - 名称: cryoSPARC (ver. 2.14) 詳細: Ab initio reconstruction of 2 classes followed by heterogenous refinement using the models generated in cryoSPARC v2.14