Interacting targets of the farnesyl of transducin gamma-subunit.
Interacting targets of the farnesyl of transducin gamma-subunit.
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DOI：
10.1021/bi800359h
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发表时间：
2008-08-12
期刊：
影响因子：
2.9
通讯作者：
Fukada, Yoshitaka
中科院分区：
文献类型：
--
作者：
Katadae, Maiko;Hagiwara, Ken'ichi;Wada, Akimori;Ito, Masayoshi;Umeda, Masato;Casey, Patrick J.;Fukada, Yoshitaka
G蛋白γ亚基的C端半胱氨酸残基被异戊二烯化和羧基甲基化，这些翻译后修饰对于感光细胞G蛋白转导素（Tα/Tβγ）的功能是必不可少的。为了探索法呢基介导的分子相互作用，我们研究了Tβγ类似物的分子靶标，该Tβγ类似物被工程化以具有光反应性法呢基类似物（3-叠氮苯氧基）香叶基（POG），其共价结合至Tγ的C-末端半胱氨酸。POG修饰的Tβγ进一步通过C端羧基的甲基化进行修饰，这复制了一套完整的已知Tβγ转录后修饰。游离态光反应性Tβγ类似物的光亲和标记实验表明，Tβ与Tγ的POG基团相互作用。在三聚体Tα/Tβγ复合物中，除了同时亲和标记Tβ外，POG部分还与Tα交联。当光反应性Tβγ与Tα和光活化视紫红质（Rh*）在视杆细胞外节（ROS）膜上重组时，POG不仅与Tα和Tβ相互作用，而且与Rh* 和膜磷脂相互作用。采用多种脂质结合探针通过ELISA分析交联的磷脂物质，其揭示了磷脂酰乙醇胺（PE）和磷脂酰丝氨酸（PS）作为ROS膜中POG相互作用的选择性磷脂。这些结果表明，Tγ的修饰基团在蛋白质-蛋白质和蛋白质-膜相互作用中起着积极的作用，并表明法呢基-PE/PS相互作用可能支持转导素和Rh* 之间有效形成信号三元复合物。
G protein γ-subunits are isoprenylated and carboxyl methylated at the C-terminal cysteine residue, and the set of the posttranslational modifications is indispensable for the function of the photoreceptor G protein transducin (Tα/Tβγ). To explore farnesyl-mediated molecular interactions, we investigated molecular targets of a Tβγ analogue that was engineered to have a photoreactive farnesyl analogue, (3-azidophenoxy)geranyl (POG), covalently bound to the C-terminal cysteine of Tγ. POG-modified Tβγ was further subjected to modification by methylation at the C-terminal carboxyl group, which copies a complete set of the known posttranscriptional modifications of Tβγ. Photoaffinity labeling experiment with the photoreactive Tβγ analogue in its free form indicated that the POG moiety of Tγ interacted with Tβ. In the trimeric Tα/Tβγ complex, the POG moiety was cross-linked with Tα in addition to concurrent affinity labeling of Tβ. When photoreactive Tβγ was reconstituted with Tα and light-activated rhodopsin (Rh*) in rod outer segment (ROS) membranes, the POG moiety interacted with not only Tα and Tβ but also Rh* and membrane phospholipids. The cross-linked phospholipid species was analyzed by ELISA employing a variety of lipid-binding probes, which revealed phosphatidylethanolamine (PE) and phosphatidylserine (PS) as selective phospholipids for POG interaction in the ROS membranes. These results demonstrate that the modifying group of Tγ plays an active role in protein−protein and protein−membrane interactions and suggest that the farnesyl−PE/PS interaction may support the efficient formation of the signaling ternary complex between transducin and Rh*.
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影响因子：
64.8
作者：
INGLESE, J;KOCH, WJ;LEFKOWITZ, RJ
通讯作者：
LEFKOWITZ, RJ
DOI：
10.1016/0005-2736(88)90192-7
发表时间：
1988-05-24
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
CHOUNG, SY;KOBAYASHI, T;INOUE, K
通讯作者：
INOUE, K
DOI：
10.1016/s1357-2725(00)00036-4
发表时间：
2000-09-01
影响因子：
4
作者：
De Busser, HM;Van Dessel, GAF;Lagrou, AR
通讯作者：
Lagrou, AR
DOI：
10.1073/pnas.93.23.12867
发表时间：
1996-11-12
影响因子：
11.1
作者：
Emoto, K;Kobayashi, T;Umeda, M
通讯作者：
Umeda, M
DOI：
10.1073/pnas.91.9.4024
发表时间：
1994-04-26
影响因子：
11.1
作者：
KAUSHAL, S;RIDGE, KD;KHORANA, HG
通讯作者：
KHORANA, HG