Genetic and molecular network of the calcium/calmodulin-dependent serine protein kinase CASK

钙/钙调蛋白依赖性丝氨酸蛋白激酶 CASK 的遗传和分子网络

• 批准号: 280629181
• 负责人: Professor Dr. Hans-Jürgen Kreienkamp
• 金额: --
• 依托单位: Institut für Humangenetik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/280629181?language=en
• 关键词: Genetic; molecular; network; calcium; calmodulin; Genetic; molecular; network; calcium; calmodulin

Next-generation sequencing is a powerful approach for unravelling the molecular basis of Mendelian disorders. Recently, we and others identified mutations in the X-linked CASK (calcium/calmodulin-dependent serine protein kinase) gene in females and males with intellectual disability with or without additional clinical features. In synapses of the central nervous system, CASK contributes to the formation of the presynaptic specialization, and to postsynaptic delivery of NMDA receptors. CASK is also redistributed to the neuronal nucleus where it binds the transcription factor Tbr1 and activates the target genes Reelin and NR2B (encoding a regulatory subunit of NMDA receptors). As NMDA receptors function as switches for memory formation by gating synaptic plasticity, the contribution of CASK to expression and transport of NMDA receptors strongly suggests a critical role of CASK in synaptic plasticity, learning and memory. Our current understanding indicates that a complex genetic and molecular synaptic network determines the phenotypic outcome of individuals with a CASK mutation. Phenotypic variability suggests that there are a number of modifier genes which affect CASK-related pathways. On the protein and cellular level, CASK acts at three different locations in neurons in different protein complexes, and it is currently unclear which of these complexes is relevant for disease. Our goals are to1) establish a genotype-phenotype correlation in males with a CASK mutation by analyzing CASK transcripts and protein in patient-derived cells.2) identify modifier genes responsible for differences in phenotypic expression of females with a heterozygous deleterious CASK mutation. We will use an extreme phenotype study design by defining individuals who are at both ends of a phenotype distribution. Whole exome sequencing on individuals of both groups will help to identify rare sequence variants enriched in one group.3) characterize the effect of CASK missense mutations (p.Y268H, p.L354P, p.P396S, p.Y723C and p.W914R) on transcriptional regulation of specific target genes of the CASK-Tbr1 transcriptional activator complex. We will carry out dual luciferase reporter assays in primary cortical neurons derived from Cask knockout mice expressing wild-type or mutant CASK. 4) analyze the effect of CASK missense mutations on specific protein-protein interactions and on intracellular trafficking of neurotransmitter receptors. CASK wildtype and mutants will be expressed in neurons derived from Cask-deficient mice, and the effect of CASK mutations on synaptogenesis and spinogenesis will be analyzed by immunocytochemistry and confocal microscopy. We will also determine the cell surface level of NMDA receptors by using live-cell surface immunostaining and biotinylation assays.5) study the in vivo effects of a selected CASK mutation in a Cask knock-in mouse, which will be analyzed with respect to synapse formation, neuronal morphology, and behavior.

下一代测序是揭示孟德尔疾病分子基础的有力方法。最近，我们和其他人在女性和具有其他临床特征的智障女性和智障男性中鉴定了X连锁木桶（钙/钙调蛋白依赖性丝氨酸蛋白激酶）基因的突变。在中枢神经系统的突触中，木桶有助于形成突触前的专业化和突触后NMDA受体的递送。 CASK还将其重新分布在结合转录因子TBR1的神经元核中，并激活靶基因reelin和NR2B（编码NMDA受体的调节亚基）。随着NMDA受体通过门控突触可塑性的开关形成了记忆的开关，CASK对NMDA受体的表达和运输的贡献强烈表明CASK在突触可塑性，学习和记忆中的关键作用。我们目前的理解表明，复杂的遗传和分子突触网络决定了桶突变个体的表型结果。表型变异性表明，有许多影响与木桶相关途径的修饰基因。在蛋白质和细胞水平上，木桶在不同蛋白质复合物的神经元中的三个不同位置作用，目前尚不清楚这些复合物中的哪一个与疾病有关。我们的目标是1）通过分析患者来源的细胞中的木桶转录物和蛋白质，在男性中建立一个基因型 - 表型相关性。2）确定带有异性杂志Deletious Cask突变的雌性表型的修饰剂基因。我们将通过定义表型分布两端的个体来使用极端的表型研究设计。对两组个体的整个外显子组测序将有助于识别富含一组的稀有序列变体。3）表征库氏错义突变（P.Y268H，P.L354P，P.L354P，P.396S，P.Y723C和P.W914R）对Cask-Tegent of Cask-trbbr1转录基因转录基因转录基因转录基因的影响。我们将在源自表达野生型或突变体桶的桶敲除小鼠的原代皮质神经元中进行双荧光素酶报告基因测定。 4）分析木桶错义突变对特定蛋白质蛋白相互作用以及神经递质受体的细胞内运输的影响。 CASK WILDTYPE和突变体将在源自木桶缺乏小鼠的神经元中表达，并且将通过免疫细胞化学和共焦显微镜分析桶突变对突触发生和旋转生成的影响。我们还将通过使用活细胞表面免疫染色和生物素化测定来确定NMDA受体的细胞表面水平。5）研究CASK敲入小鼠中选定的CASK突变的体内效应，该效果将针对突触形成，神经元形态和行为进行分析。