The role and molecular mechanism of the ectodomain shedding of HB-EGF

HB-EGF胞外域脱落的作用及分子机制

• 批准号: 11480214
• 负责人: MEKADA Eisuke
• 金额: $ 9.79万
• 依托单位: Osaka University (2000)Kurume University (1999)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11480214/
• 关键词: LPA; HB-EGF; Transactivation; G-oritein-coupled receptors; Ectodomain shedding; エクトドメインシェディング; プロテインキナーゼC; MAPキナーゼキナーゼ; リゾフォスファチジン酸; メタロプロテアーゼ

The ectodomain of the transmembrane form of HB-EGF (proHB-EGF) is cleaved at the cell surface by proteases, yielding a soluble growth factor. A number of stimuli including TPA and calcium ionophore accelerate this cleavage. However, proHB-EGF is shed constitutively under normal culture conditions without any particular stimuli. In this study we showed that constitutive cleavage resulted largely from factor (s) contained in supplemented FCS in a culture medium. Analysis of serum factors using monkey kidney-derived Vero cells revealed that lysophosphatidic acid is a major factor in FCS for stimulation of proHB-EGF shedding. Signaling mechanism downstream of LPA was also studied. Analysis including several dominant negative and constitutively active mutants or pharmacological inhibitors revealed Ras-MAPK cascade is critical for LPA-induced shedding of proHB-EGF.

HB-EGF跨膜形式的胞外域（proHB-EGF）在细胞表面被蛋白酶切割，产生可溶性生长因子。包括TPA和钙离子载体在内的许多刺激物加速这种分裂。然而，proHB-EGF在正常培养条件下组成性脱落，没有任何特殊的刺激。在这项研究中，我们表明组成性切割主要是由培养基中补充FCS中所含的因子引起的。使用猴肾衍生的Vero细胞的血清因子的分析显示，溶血磷脂酸是FCS中刺激proHB-EGF脱落的主要因子。并对LPA下游信号转导机制进行了研究。包括几个显性负性和组成性活性突变体或药理学抑制剂的分析显示，Ras-MAPK级联是LPA诱导的proHB-EGF脱落的关键。

项目成果

Yu,X.,etc: "Integrin-dependent EGF Receptor Activation at cell-cell Contact Sites."J.Cell Sci.. 113. 2139-2147 (2000)

Yu，X.，等：“细胞-细胞接触位点的整合素依赖性 EGF 受体激活。”J.Cell Sci.. 113. 2139-2147 (2000)

Tsuneoka, M.and Mekada, E.: "Ras/MEX signaling suppresses Myc-dependent apoptosis in cells transformed by c-myc and activated ras."Oncogene. 19. 115-123 (2000)

Tsuneoka, M. 和 Mekada, E.：“Ras/MEX 信号传导抑制由 c-myc 转化并激活 ras 的细胞中 Myc 依赖性细胞凋亡。”癌基因。

Tsuneoka,M.: "Ras/MEK signaling suppresses Mycdependent apoptosis in cells transformed by c-myc and activated ras."Oncogene. (in press).

Tsuneoka,M.：“Ras/MEK 信号传导抑制 c-myc 转化的细胞中 Myc 依赖性细胞凋亡并激活 ras。”癌基因。

Nakamura, K., Mitamura, T., Takahashi, T., Kobayashi, T.and Mekada, E.: "Importance of the Major Extracellular Domain of CD9 and the EGF-like Domain of HB-EGF for Upregulation of Binding and Activity."J.Biol.Chem.. 275. 18284-18290 (2000)

Nakamura, K.、Mitamura, T.、Takahashi, T.、Kobayashi, T. 和 Mekada, E.：“CD9 的主要细胞外结构域和 HB-EGF 的 EGF 样结构域对于上调结合和活性的重要性

Miyado, K., Yamada, G., Yamada, S., Hasuwa, H., Nakamura, Y., Ryu, F., Suzuki, K., Kosai, K., Inoue, K., Ogura, A., Okabe, M.and Mekada, E.: "Requirement of CD9 on the egg plasma membrane for fertilization."Science. 287. 321-324 (2000)

Miyado, K.、Yamada, G.、Yamada, S.、Hasuwa, H.、Nakamura, Y.、Ryu, F.、Suzuki, K.、Kosai, K.、Inoue, K.、Ogura, A.、