The role of WWP-family E3 ubiquitin ligases in neuronal development and function

WWP 家族 E3 泛素连接酶在神经元发育和功能中的作用

• 批准号: 310039974
• 负责人: Dr. Hiroshi Kawabe
• 金额: --
• 依托单位: Abteilung Molekulare Neurobiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/310039974?language=en
• 关键词: role; WWP; family; E3; ubiquitin

Ubiquitination is a posttranslational modification catalyzed by the sequential action of three classes of enzymes, E1, E2 enzymes, and E3 Ub ligases. Substrate specificity of ubiquitination is mainly determined by the E3 ligases, of which some 600 different isoforms are encoded in the human genome. Substrate proteins can be conjugated either with the monomeric form of Ub (monoubiquitination) or with a tandem poly-Ub chain (polyubiquitination). Monoubiquitination affects multiple protein characteristics and controls, for instance, endocytosis of receptors, DNA repair, or virus budding. The consequence of polyubiquitination depends on the type of the poly-Ub chain. To form a poly-Ub chain, the C-terminal glycine residue of one Ub is conjugated to a lysine residue on the surface of the donor Ub (K6, K11, K27, K29, K33, K48, or K63). K48-linked poly-Ub chains are recognized by the proteasome, where the target protein is degraded, while K63-linked poly-Ub chains are involved in the proteasome-independent regulation of protein functions. Interestingly, K63-linked poly-Ub chains are almost as abundant as K48-linked chains in the mammalian brain, indicating that K-63 linked chain-dependent regulation of cellular processes may be as important as Ub mediated proteasomal degradation. WWP1 and WWP2 (WWP1/2) are members of the Nedd4 superfamily of E3 ligases. Nedd4 family E3 ligases regulate the expression, localization, or function of substrates mainly in a proteasome-independent manner. Consistently, WWP1/2 as well as other Nedd4 superfamily E3 ligases preferentially conjugate mono-Ub or K63-linked poly-Ub chains rather than K48-linked poly-Ub chains. Although the molecular machinery involved in the regulation of monoubiquitination or K63-linked polyubiquitination in cultured non-neuronal cells has been explored to a substantial degree, our understanding of such 'non-proteasomal' roles of ubiquitination in nerve cell development and function in vivo is very rudimentary. We reported recently that Nedd4-1 and Nedd4-2 play key roles in neurite branching (Kawabe et al., Neuron 65, 358, 2010; Hsia et al., Proc. Natl. Acad. Sci. U.S.A. 111, 13205, 2014). Another Nedd4 superfamily member, Smurf1, is crucial for axon acquisition. In contrast, the roles of WWP1/2 in developing and mature neurons are essentially unknown. We have started to address this issue systematically, performed a preliminary characterization of WWP1/2 double KO mice, and discovered several prominent phenotypic changes in axon formation, migration, and synapse formation in double KO neurons. In the project proposed here, we will study the mechanisms through which WWP1/2 regulate axon formation, neuronal migration, and synapse formation, by identifying and characterizing the substrates of WWP1/2 and by determining how WWP E3 ligases are regulated via upstream signaling pathways.

泛素化是由三类酶（E1、E2酶和E3 Ub连接酶）的顺序作用催化的翻译后修饰。泛素化的底物特异性主要由E3连接酶决定，其中约600种不同的异构体在人类基因组中编码。底物蛋白可以与单体形式的Ub（单泛素化）或串联的多聚Ub链（多泛素化）缀合。Monoubiquitination影响多种蛋白质特征和控制，例如，受体的内吞作用，DNA修复或病毒出芽。多聚泛素化的结果取决于多聚泛素链的类型。为了形成聚Ub链，将一个Ub的C-末端甘氨酸残基与供体Ub表面上的赖氨酸残基缀合（K6、K11、K27、K29、K33、K48或K63）。K48连接的聚Ub链被蛋白酶体识别，在蛋白酶体中靶蛋白被降解，而K63连接的聚Ub链参与蛋白质功能的蛋白酶体非依赖性调节。有趣的是，K63连接的多聚Ub链在哺乳动物脑中几乎与K48连接的链一样丰富，表明K-63连接的链依赖性细胞过程调节可能与Ub介导的蛋白酶体降解一样重要。WWP 1和WWP 2（WWP 1/2）是E3连接酶的Nedd 4超家族的成员。Nedd 4家族E3连接酶主要以不依赖蛋白酶体的方式调节底物的表达、定位或功能。一致地，WWP 1/2以及其他Nedd 4超家族E3连接酶优先缀合单Ub或K63连接的多聚Ub链，而不是K48连接的多聚Ub链。虽然在培养的非神经元细胞的monoubiquitination或K63连接的polyubiquitination的调节所涉及的分子机制已被探索到相当程度，我们的理解这样的“非蛋白酶体”的作用，在神经细胞的发育和功能在体内的泛素化是非常基本的。我们最近报道Nedd 4 -1和Nedd 4 -2在神经突分支中起关键作用（Kawabe et al.，Neuron 65，358，2010; Hsia等人，Proc. Natl. Acad. Sci. U.S.A. 111，13205，2014）。另一个Nedd 4超家族成员Smurf 1对轴突的获得至关重要。相反，WWP 1/2在发育和成熟神经元中的作用基本上是未知的。我们已经开始系统地解决这个问题，进行了WWP 1/2双KO小鼠的初步表征，并发现了双KO神经元中轴突形成，迁移和突触形成的几个突出的表型变化。在这里提出的项目中，我们将研究WWP 1/2调节轴突形成，神经元迁移和突触形成的机制，通过识别和表征WWP 1/2的底物，并确定WWP E3连接酶如何通过上游信号通路进行调节。

项目成果

Deletion of LRRTM1 and LRRTM2 in adult mice impairs basal AMPA receptor transmission and LTP in hippocampal CA1 pyramidal neurons

• DOI: 10.1073/pnas.1803280115
• 发表时间: 2018-06-05
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Bhouri, Mehdi;Morishita, Wade;Malenka, Robert
• 通讯作者: Malenka, Robert

Polarity Acquisition in Cortical Neurons Is Driven by Synergistic Action of Sox9-Regulated Wwp1 and Wwp2 E3 Ubiquitin Ligases and Intronic miR-140

• DOI: 10.1016/j.neuron.2018.10.008
• 发表时间: 2018-12-05
• 期刊: NEURON
• 影响因子: 16.2
• 作者: Ambrozkiewicz, Mateusz C.;Schwark, Manuela;Kawabe, Hiroshi
• 通讯作者: Kawabe, Hiroshi