Funtional analysis of Rhes, a novel Ras family protein, in neuronal cell

新型 Ras 家族蛋白 Rhes 在神经元细胞中的功能分析

• 批准号: 14570125
• 负责人: KARIYA Ken-ichi
• 金额: $ 1.98万
• 依托单位: University of the Ryukyus
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14570125/
• 关键词: Rhes; Ras; MAP4K; Rap2; Neuron; Rasファミリー; 神経細胞; 低分子量GTP結合蛋白質; シグナル伝達

Rhes is a member of the Ras family small GTP-binding proteins. Rhes is expressed abundantly in brain, especially in striatum, and thus designated Ras homologue enriched in striatum. In the present study, we aimed at identifying a downstream effector molecule of Rhes thereby gaining insights into Rhes's neuronal function. Rhes's effector-binding domain is different from those of typical Ras homologue, suggesting interaction of Rhes with non-typical Ras effectors. Only one member of Ras family, Rap2, shares similar effector-binding region with Rhes. Rap2 shares Phe residue at the 8th position of effector-binding domain with Rhes, where Ras has Ser. Rap2 is expressed in brain and implicated in neuronal functions as well. We therefore reasoned that Rhes and Rap2 could share common non-typical Ras effectors. We used the yeast two-hybrid screening and affinity purification-mass spectrometry approach to search for Rlies-or Rap2-binding proteins. Unexpectedly, we isolated different binding proteins for Rhes and Rap2, such as ARMS(for Rhes) and MAP4K4(for Rap2). ARMS is a downstream molecule of NGF receptor, while MAP4K4's Drosophila homologue regulates neuronal axon targeting. Further studies are necessary to clarify physiological significances of these findings.

Rhes是RAS家族小GTP结合蛋白的成员。恒星在大脑中大量表达，尤其是在纹状体中，因此被指定为富含纹状体的Ras同源物。在本研究中，我们旨在鉴定恒星的下游效应分子，从而获得对Rhes神经元功能的见解。 Rhes的效应效应结构域不同于典型的RAS同源物的效应域，这表明Rhes与非典型RAS效应子的相互作用。 RAS家族的RAP2只有一名成员与Rhes共享类似的效应器结合区域。 RAP2与Rhes共享PHE残留物，在效应子结合域的第8位，Ras具有Ser。 RAP2在大脑中表达，也与神经元功能有关。因此，我们认为Rhes和Rap2可以共享常见的非典型RAS效应子。我们使用了酵母两杂交筛选和亲和力纯化质谱法来搜索RLIES-or RAP2结合蛋白。出乎意料的是，我们分离了Rhes和Rap2的不同结合蛋白，例如ARM（用于Rhes）和Map4K4（对于Rap2）。臂是NGF受体的下游分子，而MAP4K4的果蝇同源物调节神经元轴突靶向。需要进一步的研究来阐明这些发现的生理意义。

项目成果

Machida, N., et al.: "Mitogen-activated protein kinase kinase kinase kinase 4 as a putative effector of Rap2 to activate the c-Jun N-terminal kinase"J.Biol.Chem.. (in press). (2004)

Machida, N. 等人：“丝裂原激活的蛋白激酶激酶激酶 4 作为 Rap2 的推定效应子来激活 c-Jun N 末端激酶”J.Biol.Chem..（出版中）。

Machida, N., Umikawa, M., Takei, K., Sakima, N., Myagmar, B.E., Taira, K., Uezato, H., Ogawa, Y., Kariya, K.: "Mitogen-activated protein kinase kinase kinase kinase 4 as a putative effector of Rap2 to activate the c-Jun N-terminal kinase."J.Biol.Chem.. (i

Machida，N.，Umikawa，M.，Takei，K.，Sakima，N.，Myagmar，B.E.，Taira，K.，Uezato，H.，Okawa，Y.，Kariya，K.：“丝裂原激活蛋白激酶

Kido, M., et al.: "Critical function of the Ras-associating domain as a primary Ras-binding site for regulation of Saccharomyces cerevisiae adenylyl cyclase"J.Biol.Chem.. 277・5. 3117-3123 (2002)

Kido, M., et al.：“Ras 相关结构域作为酿酒酵母腺苷酸环化酶调节的主要 Ras 结合位点的关键功能”J.Biol.Chem.. 277·5 (2002)。