Identification of G Protein α Subunit-Palmitoylating Enzyme
Identification of G Protein α Subunit-Palmitoylating Enzyme
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DOI：
10.1128/mcb.01144-08
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发表时间：
2009-01-15
影响因子：
5.3
通讯作者：
Fukata, Masaki
中科院分区：
文献类型：
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作者：
Tsutsumi, Ryouhei;Fukata, Yuko;Fukata, Masaki
异源三聚体G蛋白α亚基（G α）通过可逆的脂质棕榈酰化作用靶向质膜的细胞质面，并将G蛋白偶联受体（GPCR）的信号传递给其效应物。通过筛选23个DHHC模体（Asp-His-His-Cys）棕榈酰转移酶，我们鉴定了DHHC 3和DHHC 7为G α棕榈酰化酶。DHHC 3和DHHC 7在HEK 293 T细胞中稳健地棕榈酰化G α（q）、G α（s）和G α（i2）。DHHC 3和DHHC 7的敲低降低了G α（q/11）棕榈酰化并将其从质膜重新定位到细胞质中。光转换分析表明，G alpha（q）快速穿梭于质膜和高尔基体之间，DHHC 3特异性定位于高尔基体。光漂白研究后的荧光恢复表明，DHHC 3和DHHC 7是这种连续G α（q）穿梭所必需的。此外，DHHC 3和DHHC 7敲低阻断了α（1A）-肾上腺素能受体/G α（q/11）介导的信号通路。总之，我们的研究结果表明，DHHC 3和DHHC 7通过控制G α定位到质膜来调节GPCR介导的信号转导。
The heterotrimeric G protein alpha subunit (G alpha) is targeted to the cytoplasmic face of the plasma membrane through reversible lipid palmitoylation and relays signals from G-protein-coupled receptors (GPCRs) to its effectors. By screening 23 DHHC motif (Asp-His-His-Cys) palmitoyl acyl-transferases, we identified DHHC3 and DHHC7 as G alpha palmitoylating enzymes. DHHC3 and DHHC7 robustly palmitoylated G alpha(q), G alpha(s), and G alpha(i2) in HEK293T cells. Knockdown of DHHC3 and DHHC7 decreased G alpha(q/11) palmitoylation and relocalized it from the plasma membrane into the cytoplasm. Photoconversion analysis revealed that G alpha(q) rapidly shuttles between the plasma membrane and the Golgi apparatus, where DHHC3 specifically localizes. Fluorescence recovery after photobleaching studies showed that DHHC3 and DHHC7 are necessary for this continuous G alpha(q) shuttling. Furthermore, DHHC3 and DHHC7 knockdown blocked the alpha(1A)-adrenergic receptor/G alpha(q/11)-mediated signaling pathway. Together, our findings revealed that DHHC3 and DHHC7 regulate GPCR-mediated signal transduction by controlling G alpha localization to the plasma membrane.