Screening and characterization of BMP-specific R-Smads binding proteins

BMP 特异性 R-Smads 结合蛋白的筛选和表征

• 批准号: 13671554
• 负责人: IMAMURA Takeshi
• 金额: $ 2.3万
• 依托单位: Japanese Foundation for Cancer Research
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13671554/
• 关键词: BMPs; Smads; Signal transduction

Bone morphogenetic proteins (BMPs), members of the transforming growth factor-β (TGF-β) superfamily, were originally identified as osteoinductive proteins in bone that induce ectopic bone and cartilage formation in vivo. BMPs bind to type I and type II serine/threonine kinase receptors, BMPR-I and II. Smad proteins play central roles in intracellular signaling by BMPs. Eight different Smad proteins have been identified in mammals, and are classified into three subgroups, i. e. receptor-regulated Smads (R-Smads), a common-partner Smad (Co-Smad), and inhibitory Smads (I-Smads). BMP-specific R-Smads, Smads 1,5 and 8, transiently and directly interact with activated BMPR-Is, and become phosphorylated. Smad1/5/8 then form heteromeric complexes with Co-Smad, Smad4, and translocate into the nucleus where they regulate transcription of various target genes. In contrast, I-Smads, including Smad6 and Smad7, stably bind to BMPR-Is and compete with Smad1/5/8 for activation, resulting in inhibition of BMP signaling.In this project, we examined the function of Smad ubiquitin regulatory factor(Smurf) 1 as a Smad binding protein. Smurf1 was originally identified as an E3 ubiquitin ligase for Smad1/5. We demonstrated that Smurf1 associates with type I receptors for BMPs through the I-Smads, and induced their ubiquitination and degradation. Smurf1 thus controls BMP signaling with and without I-Smads through multiple mechanisms.Next, we clarified the mechanism of nuclear export and membrane localization of Smurf1-I-Smad complex. Smurf1 binds to CRM1, and Smurf1-I-Smad complex translocates from the nucleus to the cytoplasm. Then Smurf1-I-Smad complex locates to cell membrane through C2 domain of Smurf1.

骨形态发生蛋白（BMP）是转化生长因子-β（TGF-β）超家族的成员，最初被鉴定为骨骼中骨诱导蛋白的骨诱导蛋白，可在体内诱导骨骨和软骨形成。 BMP与I型和II型丝氨酸/苏氨酸激酶受体BMPR-I和II结合。 SMAD蛋白在BMP的细胞内信号传导中起着核心作用。已经在哺乳动物中鉴定出八种不同的SMAD蛋白，并分为三个亚组，即接收器调节的SMADS（R-SMADS），一个普通伴侣SMAD（Co-Smad）和抑制性SMADS（I-SMADS）。 BMP特异性的R-SMADS，SMADS 1,5和8，瞬时并直接与活化的BMPR-IS相互作用，并变得磷酸化。然后，Smad1/5/8与co-SMAD，SMAD4形成异构复合物，并转移到核中，它们调节各种靶基因的转录。相反，包括SMAD6和SMAD7在内的I-SMAD稳定与BMPR-IS结合，并与SMAD1/5/8竞争激活，从而抑制了BMP信号。在此项目中，我们检查了SMAD泛素调节因子（SMURF）1作为SMAD结合蛋白的功能。 Smurf1最初被鉴定为SMAD1/5的E3泛素连接酶。我们证明了SMURF1通过I-SMADS与BMP的I型受体相关联，并诱导其泛素化和降解。因此，SMURF1通过多种机制控制有或没有I-SMADS的BMP信号传导。接头，我们将核输出和膜定位的机理储存了Smurf1-i-Smad复合物的膜定位。 SMURF1与CRM1结合，Smurf1-I-Smad复合物从核转移到细胞质。然后Smurf1-I-Smad复合物通过SMURF1的C2结构域定位在细胞膜上。

项目成果

Nishimori S, Tanaka Y, Chiba T, Fujii M, Imamura T, Miyazono K, Ogasawara T, Kawaguchi H, Igarashi T, Fujita T, Tanaka K, Toyoshima H.: "Smad-mediated transcription is required for transforming growth factor-beta 1-induced p57(Kip2) proteolysis in osteobl

Nishimori S、Tanaka Y、Chiba T、Fujii M、Imamura T、Miyazono K、Ogasawara T、Kawaguchi H、Igarashi T、Fujita T、Tanaka K、Toyoshima H.：“转化生长因子-β 需要 Smad 介导的转录

Ebisawa T, Fukuchi M, Murakami G, Chiba T, Tanaka K, Imamura T, Miyazono K: "Smurf1 interacts with transforming growth factor-beta type I receptor through Smad7 and induces receptor degradation"J Biol Chem.. 276. 12477-12480 (2001)

Ebisawa T、Fukuchi M、Murakami G、Chiba T、Tanaka K、Imamura T、Miyazono K：“Smurf1 通过 Smad7 与转化生长因子-β I 型受体相互作用，并诱导受体降解”J Biol Chem.. 276. 12477-12480

Suzuki C, Murakami G, Fukuchi M, Shimanuki T, Shikauchi Y, Imamura T, Miyazono K: "Smurf1 regulates the inhibitory activity of Srnad7 by targeting Smad7 to the plasma membrane."J Biol Chem.. 277. 39919-39925 (2002)

Suzuki C、Murakami G、Fukuchi M、Shimanuki T、Shikauchi Y、Imamura T、Miyazono K：“Smurf1 通过将 Smad7 靶向质膜来调节 Srnad7 的抑制活性。”J Biol Chem.. 277. 39919-39925 (2002

Midorikawa Y, Ishikawa S, Iwanari H, Imamura T, Sakamoto H, Miyazono K, Kodama T, Makuuchi M, Aburatani H: "Glypican-3, ova-expressed in hepatocellular carcinoma, modulates FGF2 and BMP-7 signaling."Int J Cancer.. 103. 455-465 (2003)

Midorikawa Y、Ishikawa S、Iwanari H、Imamura T、Sakamoto H、Miyazono K、Kodama T、Makuuchi M、Aburatani H：“肝细胞癌中 ova 表达的 Glypican-3，调节 FGF2 和 BMP-7 信号传导。”Int J

Nishihara, A.et al.: "Functional Heterogeneity of Bone Morphogenetic Protein Receptor-II Mutants Found in Patients with Primary Pulmonary Hypertension"Mol Biol Cell. 13. 3055-3063 (2002)

Nishihara, A.等人：“原发性肺动脉高压患者中发现的骨形态发生蛋白受体-II 突变体的功能异质性”Mol Biol Cell。