Acetylation of SUMO paralogs as a determinant of SUMO-mediated protein networks

SUMO 旁系同源物的乙酰化作为 SUMO 介导的蛋白质网络的决定因素

• 批准号: 242915414
• 负责人: Professor Dr. Stefan Müller
• 金额: --
• 依托单位: Institut für Biochemie II
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/242915414?language=en
• 关键词: Acetylation; SUMO; paralogs; determinant; mediated; Acetylation; SUMO; paralogs; determinant; mediated

The post-translational modification (PTM) of proteins through phosphorylation, acetylation or ubiquitylation is a central mechanism for the control of cellular signalling networks. A general principle is the selective recognition of the modified protein by a specific interaction domain. Modification by the ubiquitin-related SUMO protein also modulates specific protein-protein interactions thereby regulating various cellular signalling processes. Attachment of SUMO typically earmarks a protein for the recognition by a binding partner that contains a SUMO interaction motif (SIM). Prominent examples are the targeting of sumoylated RanGAP1 to RanBP2 or the SUMO/SIM-dependent assembly of PML nuclear bodies (NBs). Canonical SIMs are characterized by a stretch of hydrophobic residues, which interacts with a hydrophobic pocket on the surface of SUMO. In a subset of SIM modules acidic residues flank the hydrophobic core and enhance the binding to SUMO via electrostatic interactions with a basic interface on the modifier. Despite these relatively detailed molecular insights in SUMO/SIM interactions it is unclear how specificity and dynamics of these interactions are regulated. We recently unravelled the importance of PTMs for this process. We initially found that in a subset of SIM-containing proteins serine or threonine residues that juxtapose the hydrophobic region are phosphorylated. The additional negative charges of phosphorylated residues in these phosphoSIMs enhance the binding to the basic interface of SUMO. Very recently we defined site-specific acetylation of lysine residues within this basic interface as a novel regulatory principle in the control of SUMO/SIM interactions. We could show that acetylation of SUMO1 at K37 or SUMO2 at K33 still allows binding to RanBP2, but precludes the interaction with PIAS family members, PML or Daxx. Accordingly, SUMO affected the assembly of PML NBs and in particular prevented the SIM-dependent recruitment of the co-repressor Daxx to these structures. Importantly, in biochemical experiments we could further demonstrate that K33 acetylated SUMO2 serves as a binding platform for the Bromodomain (BRD) containing protein p300. In this proposal we aim to delineate how acetylation controls SUMO-mediated protein networks. We aim to identify specific substrates that are regulated by acetyl-SUMO modification and seek to get insight how this affects selected cellular pathways, in particular the control of gene expression. Finally, we want to unravel how the acetylation of SUMO is regulated.Within the funding period we anticipate to reach the following milestones:1. Decipher a specific acetyl-code on SUMO paralogs that determines the selectivity of SUMO/SIM and acetyl-SUMO/BRD interactions.2. Define targets of the acetyl-SUMO-code and delineate its impact on gene expression.3. Identify the regulatory components and physiological stimuli that control acetylation of SUMO paralogs.

通过磷酸化，乙酰化或泛素化的蛋白质翻译后修饰（PTM）是控制细胞信号网络的中心机制。一般原理是特定相互作用域对修饰蛋白的选择性识别。通过泛素相关的SUMO蛋白修饰还调节了特定的蛋白质 - 蛋白质相互作用，从而调节了各种细胞信号传导过程。 Sumo的附着通常将包含相互作用基序（SIM）的结合伴侣识别的蛋白质指定。突出的例子是将sumoypation的rangap1靶向ranbp2或pml核体（NBS）的SUMO/SIM依赖性组件。规范的SIMS的特征是一系列疏水残基，这些残基与Sumo表面的疏水口袋相互作用。在SIM模块的子集中，酸性残基侧面疏水芯，并通过静电相互作用与修饰符上的基本界面增强与SUMO的结合。尽管这些相对详细的分子见解在Sumo/Sim相互作用中，但尚不清楚如何调节这些相互作用的特异性和动力学。我们最近揭示了PTMS对此过程的重要性。我们最初发现，在含疏水区域并置的含Sim蛋白质丝氨酸或苏氨酸残基的子集中。这些磷酸化中磷酸化残基的附加负电荷增强了与Sumo基本界面的结合。最近，我们将这种基本界面中赖氨酸残基的位点特异性乙酰化定义为Sumo/Sim相互作用控制的新调节原理。我们可以表明，在K37或SUMO2处的SUMO1在K33处的乙酰化仍然允许与RANBP2结合，但排除了与PIAS家族成员PML或DAXX的相互作用。因此，Sumo影响了PML NBS的组装，尤其是阻止了将共抑制剂DAXX募集到这些结构中的SIM依赖性募集。重要的是，在生化实验中，我们可以进一步证明K33乙酰化SUMO2是含有蛋白质p300的溴结构域（BRD）的结合平台。在此提案中，我们旨在描述乙酰化如何控制SUMO介导的蛋白质网络。我们旨在确定受乙酰基 - 苏姆修饰调节的特定底物，并寻求洞悉这如何影响选定的细胞途径，尤其是基因表达的控制。 最后，我们想解开如何调节相扑的乙酰化。在我们期望达到以下里程碑的资金时期：1。 在Sumo旁系同源物上解密特定的乙酰代码，该代码决定了SUMO/SIM和乙酰 - 苏糖/BRD相互作用的选择性。2。 定义乙酰 - 苏属代码的靶标，并描绘其对基因表达的影响3。 确定控制相对旁同产的乙酰化的调节成分和生理刺激。