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，最初被鉴定为骨中的骨诱导蛋白，可诱导体内异位骨和软骨的形成。 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发挥核心作用。已在哺乳动物中鉴定出八种不同的 Smad 蛋白，并将其分为三个亚组，即： e.受体调节型 Smad (R-Smad)、共同伴侣 Smad (Co-Smad) 和抑制性 Smad (I-Smad)。 BMP 特异性 R-Smad、Smad 1,5 和 8 短暂地直接与激活的 BMPR-Is 相互作用，并被磷酸化。然后，Smad1/5/8 与 Co-Smad、Smad4 形成异聚复合物，并易位到细胞核中，在细胞核中调节各种靶基因的转录。相比之下，I-Smads（包括Smad6和Smad7）稳定地与BMPR-Is结合，并与Smad1/5/8竞争激活，从而抑制BMP信号传导。在本项目中，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 Smurf1 通过 I-Smad 与 BMP 的 I 型受体结合，并诱导其泛素化和降解。因此，Smurf1通过多种机制在有或没有I-Smads的情况下控制BMP信号传导。接下来，我们阐明了Smurf1-I-Smad复合物的核输出和膜定位机制。 Smurf1 与 CRM1 结合，Smurf1-I-Smad 复合物从细胞核转移到细胞质。然后Smurf1-I-Smad复合物通过Smurf1的C2结构域定位到细胞膜。

项目成果

Hanyu A, Ishidou Y, Ebisawa T, Shimanuki T, Imamura T, Miyazono K: "The N domain of Smad7 is essential for specific inhibition of transforming growth factor-beta signaling"J Cell Biol.. 155. 1017-1028 (2001)

Hanyu A、Ishidou Y、Ebisawa T、Shimanuki T、Imamura T、Miyazono K：“Smad7 的 N 结构域对于转化生长因子-β 信号传导的特异性抑制至关重要”J Cell Biol.. 155. 1017-1028 (2001)

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。

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