ジャーナル: Nat Struct Mol Biol / 年: 2024 タイトル: Molecular basis for Gβγ-mediated activation of phosphoinositide 3-kinase γ. 著者: Chun-Liang Chen / Ramizah Syahirah / Sandeep K Ravala / Yu-Chen Yen / Thomas Klose / Qing Deng / John J G Tesmer / 要旨: The conversion of phosphatidylinositol 4,5-bisphosphate to phosphatidylinositol 3,4,5-triphosphate by phosphoinositide 3-kinase γ (PI3Kγ) is critical for neutrophil chemotaxis and cancer metastasis. ...The conversion of phosphatidylinositol 4,5-bisphosphate to phosphatidylinositol 3,4,5-triphosphate by phosphoinositide 3-kinase γ (PI3Kγ) is critical for neutrophil chemotaxis and cancer metastasis. PI3Kγ is activated by Gβγ heterodimers released from G protein-coupled receptors responding to extracellular signals. Here we determined cryo-electron microscopy structures of Sus scrofa PI3Kγ-human Gβγ complexes in the presence of substrates/analogs, revealing two Gβγ binding sites: one on the p110γ helical domain and another on the p101 C-terminal domain. Comparison with PI3Kγ alone reveals conformational changes in the kinase domain upon Gβγ binding that are similar to Ras·GTP-induced changes. Assays of variants perturbing the Gβγ binding sites and interdomain contacts altered by Gβγ binding suggest that Gβγ recruits the enzyme to membranes and allosterically regulates activity via both sites. Studies of zebrafish neutrophil migration align with these findings, paving the way for in-depth investigation of Gβγ-mediated activation mechanisms in this enzyme family and drug development for PI3Kγ.
平均露光時間: 3.12 sec. / 電子線照射量: 55 e/Å2 / 検出モード: SUPER-RESOLUTION フィルム・検出器のモデル: GATAN K3 BIOQUANTUM (6k x 4k) 詳細: Images were collected in movie-mode at 40 frames per second
電子光学装置
エネルギーフィルター名称: GIF Quantum ER / エネルギーフィルタースリット幅: 20 eV
画像スキャン
横: 11520 / 縦: 8184 / 動画フレーム数/画像: 40
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解析
EMソフトウェア
ID
名称
バージョン
カテゴリ
1
cryoSPARC
3.3.1
粒子像選択
2
Leginon
画像取得
4
cryoSPARC
3.3.1
CTF補正
7
UCSF Chimera
1.15
モデルフィッティング
8
Coot
9.6
モデルフィッティング
10
Coot
9.6
モデル精密化
11
PHENIX
1.20-4459
モデル精密化
12
cryoSPARC
3.3.1
初期オイラー角割当
13
cryoSPARC
3.3.1
最終オイラー角割当
14
cryoSPARC
3.3.1
分類
15
cryoSPARC
3.3.1
3次元再構成
CTF補正
タイプ: PHASE FLIPPING AND AMPLITUDE CORRECTION
3次元再構成
解像度: 3.4 Å / 解像度の算出法: FSC 0.143 CUT-OFF / 粒子像の数: 167954 / アルゴリズム: BACK PROJECTION / 対称性のタイプ: POINT
原子モデル構築
プロトコル: AB INITIO MODEL / 空間: REAL / Target criteria: correlation coefficient