Structure-function relationships of protein kinase CK2

蛋白激酶CK2的结构与功能关系

• 批准号: 173792144
• 负责人: Professor Dr. Karsten Niefind
• 金额: --
• 依托单位: Institut für Biochemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/173792144?language=en
• 关键词: Structure; function; relationships; protein; kinase

Protein kinase CK2 (former name: 'casein kinase 2'), an essential and biomedically relevant enzyme ubiquitously expressed in eukaryotes, belongs to the superfamily of eukaryotic protein kinases. Depending on its localization and on the nature of its protein substrates, CK2-catalyzed phosphorylation leads to cell stabilization, e.g. by inhibition of apoptosis or stimulation of DNA repair, or to up-regulation of cell proliferation. In addition, CK2 affects several signal transduction pathways and the circadian rhythm. The so-called CK2 holoenzyme is the physiologically predominant entity with CK2 activity; it consists of two catalytically active subunits (CK2alpha) non-obligatory bound to a central dimer of regulatory subunits (CK2beta). By binding to the catalytic subunit CK2beta modifies the activity, the specificity and the stability of CK2alpha. CK2 is an attractive subject of basic research in the fields of biochemistry, cell biology and structural biology and of applied research with medical-pharmacological focus. While a first ATP-competitive CK2 inhibitor is currently investigated in clinical studies of cancer therapy, molecules interacting with CK2alpha sites outside the ATP binding cleft, such as at the CK2alpha/CK2beta interface, have drawn increased interest over the past years. The proposed project is intended to significantly contribute to both major fields, i.e. to basic as well as to applied research on CK2. Structural biology related basic research will be based on X-ray crystal structures of CK2 complexes, which will provide significant information on the substrate recognition by CK2 and the role of CK2beta during this process. Furthermore, such crystal structures will allow for obtaining insights into the dual substrate specificity of CK2 which catalyzes not only the phosphorylation of serine and threonine residues but has also been reported to accept tyrosine residues. Findings obtained in the first project phase, showing differences in the affinity of the two paralogous isoforms of human CK2alpha to CK2beta, will be further pursued, e.g. by structural studies in solution using small-angle X-ray scattering (SAXS). In addition to this, it is aimed to elucidate the structural basis of several phenomena published for non-human CK2. In the field of medical-pharmacological CK2 research, the cooperation of the two applicants during the first project phase has resulted in important outcomes that will now be further pursued: The three-dimensional structure of CK2alpha in complex with a CK2beta-competitive peptide has been the basis for the development of an assay suitable for high-throughput screening of potential CK2beta antagonists. This assay will be used in the search for new lead structures capable of inhibiting the CK2alpha/CK2beta subunit interaction. Both inhibitors found by screening and the few already known CK2beta antagonists will be optimized by rational and structure-based methods and eventually investigated in vivo.

蛋白激酶CK2（以前的名称：“酪蛋白激酶2”）是一种在真核生物中表达的必不可少的和生物医学相关的酶，属于真核生物蛋白激酶的超家族。根据其定位和蛋白质底物的性质，CK2催化的磷酸化导致细胞稳定，例如通过抑制细胞凋亡或刺激DNA修复或对细胞增殖的上调。此外，CK2会影响几种信号转导途径和昼夜节律。所谓的CK2 Holoenzyme是具有CK2活性的生理主导实体。它由两个催化活性亚基（CK2alpha）组成，与调节亚基的中央二聚体（CK2BETA）的中心二聚体结合。通过与催化亚基CK2Beta结合，可以修饰CK2alpha的活性，特异性和稳定性。 CK2是生物化学，细胞生物学和结构生物学领域的基础研究的有吸引力的主题，以及具有医学 - 药理学重点的应用研究。尽管目前在癌症治疗的临床研究中研究了第一个ATP竞争激烈的CK2抑制剂，但与ATP结合裂口外的CK2alpha位点相互作用，例如在过去几年中，例如在CK2Alpha/CK2Beta界面上，它吸引了更多的兴趣。拟议的项目旨在为这两个主要领域做出重大贡献，即基本和对CK2的应用研究。与结构生物学相关的基础研究将基于CK2复合物的X射线晶体结构，该研究将提供有关CK2的底物识别以及CK2BETA在此过程中的作用的重要信息。此外，这种晶体结构将允许对CK2的双重底物特异性获得洞察力，该特异性不仅催化丝氨酸和苏氨酸残基的磷酸化，而且还据报道接受酪氨酸残基。在第一个项目阶段获得的发现显示，将进一步追求人类CK2Alpha对CK2Beta的两个寄生虫同工型的亲和力差异，例如通过使用小角度X射线散射（SAXS）进行溶液中的结构研究。除此之外，它旨在阐明针对非人类CK2发表的几种现象的结构基础。在医学 - 药理学CK2研究领域中，在第一个项目阶段，两名申请人的合作导致了重要的结果，现在将进一步追求：CK2alpha与CK2BETA竞争力的肽的复杂性三维结构是适合于高摄影筛查CKK2BETA的高级筛选的分析的基础。该测定法将用于搜索能够抑制CK2alpha/ck2beta亚基相互作用的新铅结构。通过筛选发现的抑制剂和少数已知的CK2BETA拮抗剂都将通过理性和基于结构的方法进行优化，并最终在体内研究。