Mechanisms of insect limb development

昆虫肢体发育机制

• 批准号: 15207018
• 负责人: HAYASHI Shigeo
• 金额: $ 12.9万
• 依托单位: RIKEN
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15207018/
• 关键词: Signaling; Drosophila; imaginal disc; Notch; Nedd4; Deltex; endocytosis; ubiqitination; 付属肢; エンドサイトーシス; ユビキチン; 成虫原基; gfp; 気管; 翅; 細胞移動

Ligand-induced proteolytic cleavage and internalization of the plasma membrane receptor Notch leads to its activation. Ligand-independent, steady state internalization of Notch, however, does not lead to activation. The mechanism by which downstream effectors discriminate these bipartite modes of Notch internalization is not understood. Nedd4 is a HECT domain-containing E3 ubiquitin ligase that targets transmembrane receptors containing the PPSY motif for endocytosis. Deltex is a positive regulator of Notch signaling and encodes a putative ubiquitin ligase of the ring finger type. We show that Notch is ubiquitinated, and destabilized by Nedd4 in a manner requiring the PPSY motif in the Notch intracellular domain. Loss of Nedd4 function dominantly suppresses the Notch and Deltex mutant phenotypes and its hyper activation attenuates Notch activity. In tissue culture cells, dominant-negative form of Nedd4 blocks steady-state Notch internalization and activates Notch signaling independently of ligand binding, and this effect was further potentiated by Deltex. Nedd4 destines Deltex to degradation in a Notch-dependent manner. Nedd4 antagonizes Notch signaling by promoting internalization of Notch and degradation of Notch and Deltex. Those functions of Nedd4 may be important for the protection of unstimulated cells from sporadic activation of Notch signaling.

配体诱导的质膜受体Notch的蛋白水解裂解和内化导致其活化。然而，Notch的配体非依赖性稳态内化不会导致激活。下游效应物区分Notch内化的这些二分模式的机制尚不清楚。Nedd4是含有HECT结构域的E3泛素连接酶，其靶向含有PPSY基序的跨膜受体用于内吞作用。Deltex是Notch信号传导的正调控因子，编码环指型的推定泛素连接酶。我们表明，Notch是泛素化的，并不稳定的Nedd4的方式需要在Notch细胞内结构域的PPSY基序。Nedd4功能的丧失主要抑制Notch和Deltex突变体表型，并且其超活化减弱Notch活性。在组织培养细胞中，显性负性形式的Nedd4阻断稳态Notch内化并独立于配体结合激活Notch信号传导，并且Deltex进一步增强了这种作用。Nedd4以Notch依赖的方式使Deltex降解。Nedd4通过促进Notch的内化以及Notch和Deltex的降解来拮抗Notch信号传导。Nedd4的这些功能对于保护未受刺激的细胞免受Notch信号传导的零星激活可能是重要的。

项目成果

Kubota, K: "The role of Wg signaling in the patterning of embiyonic leg primordium in Drosophila"Developmental Biology. 257. 117-126 (2003)

Kubota, K：“Wg 信号在果蝇胚胎腿原基模式中的作用”发育生物学。

Drosophila Nedd4 regulates endocytosis of notch and suppresses its ligand-independent activation

• DOI: 10.1016/j.cub.2004.12.028
• 发表时间: 2004-12-29
• 期刊: CURRENT BIOLOGY
• 影响因子: 9.2
• 作者: Sakata, T;Sakaguchi, H;Hayashi, S
• 通讯作者: Hayashi, S

Sugimura, K: "Distinct developmental modes and lesion-induced reactions of dentrites of two classes of Drosophila sensory neurons"Journal of Neuroscience. 23. 3725-3760 (2003)

Sugimura, K：“两类果蝇感觉神经元的树突的不同发育模式和损伤诱导的反应”神经科学杂志。

Formin3 is required for assembly of the F-actin structure that mediates tracheal fusion in Drosophila

• DOI: 10.1016/j.ydbio.2004.07.035
• 发表时间: 2004-10-15
• 期刊: DEVELOPMENTAL BIOLOGY
• 影响因子: 2.7
• 作者: Tanaka, H;Takasu, E;Nose, A
• 通讯作者: Nose, A

Rac promotes epithelial cell rearrangement during tracheal tubulogenesis in Drosophila

• DOI: 10.1242/dev.00361
• 发表时间: 2003-04-01
• 期刊: DEVELOPMENT
• 影响因子: 4.6
• 作者: Chihara, T;Kato, K;Hayashi, S
• 通讯作者: Hayashi, S