Function, of MNB/DYRK1A gene cloned from "Down syndrome critical region" on chromosome 21.

从21号染色体“唐氏综合症关键区”克隆的MNB/DYRK1A基因的功能。

• 批准号: 12672138
• 负责人: ITO Fumiaki
• 金额: $ 2.11万
• 依托单位: SETSUNAN UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12672138/
• 关键词: Down syndrome; Chromosome 21; MNB; DYRK1A protein; Protein kinase; Multinucleation; DYRK1Aタンパク質; タンパク質リン酸化酵素; 多角細胞; 核移行シグナル; トリソミー; Mnb遺伝子; DYRK1A; リン酸化酵素

MNB/DYRK1A gene cloned from "Down syndrome critical region" on chromosome 21 is a strong candidate for mental retardation associated with. Down syndrome. This gene encodes a dual-specificity protein kinase whose activity depends on the phoshorylation of tyrosine residues in the activation loop. In this study, we examined the intracellular localization of MNB/DYRK1A protein in HeLa cells. Green fluorescent protein (GFP) fusion protein of MNB/DYRK1A exhibited a speckled pattern inside the nucleus in interphase. After breakdown of the nuclear envelope in mitosis, it gave a diffuse pattern and located in the cytoplasm with relative exclusion from the condensed chromatin region. Subcellular fractionation study revealed that GFP-MNB/DYRK1A was predominantly found in the soluble fraction obtained from the nuclei rather than in the nuclear matrix. GFP-MNB/DYRK1A mutant construct (Y310F/Y312F) also showed the speckled pattern, indicating that the appearance of nuclear dot is independent of phosphorylation of these tyrosine residues. Similar punctate patterns of subnuclear distribution have previously been shown for PML, SC-35, PCNA, and SUMO-1; however, con focal microscopy analysis showed that none of them colocalized with GFP-MNB/DYRK1A. In addition to the cells with the nuclear dots, we observed cells expressing GFP-MNB/DYRK1A all over the nucleus. In these cells, the multinucleation was observed, indicating that the overexpression of MNB/DYRK1A leads to multinucleation in HeLa cells. These results suggest that MNB/DYRKlA play a significant role in coordinating nuclear division (mitosis) with cytoplasmic division (cytokinesis) during cell cycle. Detailed analysis of cytoskeltal proteins such as tubulin and actin, which control cell division, is important.

从 21 号染色体上的“唐氏综合症关键区域”克隆的 MNB/DYRK1A 基因是与精神发育迟滞相关的有力候选基因。唐氏综合症。该基因编码一种双特异性蛋白激酶，其活性取决于激活环中酪氨酸残基的磷酸化。在本研究中，我们检查了 HeLa 细胞中 MNB/DYRK1A 蛋白的细胞内定位。 MNB/DYRK1A 的绿色荧光蛋白 (GFP) 融合蛋白在间期的细胞核内表现出斑点图案。有丝分裂中核膜破裂后，它呈现弥散模式并位于细胞质中，相对排除在浓缩染色质区域之外。亚细胞分级分离研究表明，GFP-MNB/DYRK1A 主要存在于从细胞核获得的可溶性级分中，而不是在核基质中。 GFP-MNB/DYRK1A 突变体构建体 (Y310F/Y312F) 也显示出斑点图案，表明核点的出现与这些酪氨酸残基的磷酸化无关。先前已在 PML、SC-35、PCNA 和 SUMO-1 中显示出类似的亚核分布模式；然而，共聚焦显微镜分析表明它们都不与 GFP-MNB/DYRK1A 共定位。除了具有核点的细胞外，我们还观察到细胞核中遍布表达 GFP-MNB/DYRK1A 的细胞。在这些细胞中，观察到多核化，表明 MNB/DYRK1A 的过度表达导致 HeLa 细胞中的多核化。这些结果表明MNB/DYRK1A在细胞周期期间协调核分裂(有丝分裂)与细胞质分裂(细胞分裂)中发挥重要作用。对控制细胞分裂的细胞骨架蛋白（例如微管蛋白和肌动蛋白）的详细分析非常重要。