在此研究中，我們發現translocated CagA 不僅表現在真核細胞質中，還表 現於細胞核內，細胞核內CagA 的表現量比細胞質多，同時，細胞核內的 CagA 具有磷酸化修飾，而 CagA 進入細胞核的方式是 phosphorylation-independent，
主要是透過胺基端序列來調控是否進入細胞核中；另外，我們也利用免疫共沉 澱法發現，細胞核內萃取液的CagA 可共沉澱 SHP-2，代表 CagA 和 SHP-2 之
間在細胞核內有交互作用，暗示著 CagA 進入細胞核內具有重要的功能和角
色。
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圖表說明
圖一、CagA 進入細胞後，可存在於真核細胞的細胞核中
(A)8×106 L428 細胞，分別取 12 μg EGFP 或 EGFP-CagA 質體 DNA 以電穿 孔的方式轉染進細胞內，二十四小時後，分別收集細胞萃取液(左)或細胞質和細胞 核萃取液(右) (B)以 lipofectamine 轉染 6.7μg 質體 DNA 進入 1.6×106 AGS 細胞，
分別收集細胞萃取液(左，293T 細胞為對照組)，收集轉染 12 小時細胞質和細胞核 萃取液(右)，經 SDS 膠體電泳，轉漬於 PVDF 膜上，利用 pY99、CagA、actin、
HDAC1 和 α-tubulin 抗體偵測蛋白質的表現。
圖一 (A)
(B)
圖二 (A)
(B)
圖二、胃幽門桿菌將 CagA 注入真核細胞的細胞質和細胞核中
胃幽門桿菌菌種26695 與 B 淋巴細胞以 MOI=100 的方式共同培養: (A)L428 細胞株，供養五小時後，加入200 μg/ml gentamicin 殺死胃幽門桿菌，再於 24、48、
72、96 小時後，收集細胞萃取液、細胞質和細胞核萃取液，跑 SDS 膠體電泳，轉 漬到PVDF 膜上，利用 CagA、actin、HDAC1 和 α-tubulin 抗體偵測蛋白質的表現 (B)共同培養 5、24 小時後，依序固定、染色和封片，以共軛焦顯微鏡觀察 CagA 表現情形 (C)胃幽門桿菌 26695 菌種以 MOI=100 的方式和 1×106 AGS 細胞共同培 養，24 小時後，分離細胞質和細胞核萃取液，跑 SDS 膠體電泳，轉漬到 PVDF 膜
(C)
圖三、CagA 進入細胞核的方式是 phosphorylation-independent
4×106 AGS 細胞轉染 20μg 質體 DNA，12 小時後，收集細胞質和細胞核萃取 液，跑 SDS 膠體電泳，轉漬於 PVDF 膜上，利用 pY99、CagA、GFP、HDAC1 和α-tubulin 抗體偵測蛋白質的表現。
圖三
圖四 (A)
(B)
圖四、胺基端序列具有決定 CagA 進入細胞核的角色
(A) truncated CagA 分別為缺乏羧基端與 EPIYA-motif 的 CagA1-892、缺乏羧 基端的CagA1-1094 以及只含有羧基端(缺乏胺基端)CagA1083-1247 (B)將 truncated CagA plasmid 轉 染 到 293T 細 胞 中 ， 確 定 truncated CagA 蛋 白 的 表 現 ， EGFP-CagA1-892、EGFP-CagA1-1094、EGFP-CagA1083-1247 融合蛋白分別為 127、
149、47 kDa (C) 4×106 AGS 細胞轉染 20μg 質體 DNA，12 小時後，收集細胞質和 細胞核萃取液，，跑SDS 膠體電泳，轉漬於 PVDF 膜上，利用 pY99、CagA、GFP、
HDAC1 和 α-tubulin 抗體偵測蛋白質的表現。
(C)
圖五、SHP-2 分子在細胞核內與 CagA 交互作用
5×106 L428 細胞，以 MOI=100 方式共同培養胃幽門桿菌菌種 26695，24 小時 後，收集細胞核萃取液，以CagA 抗體做免疫沉澱，跑 SDS 膠體電泳，用西方點