Expression of the HSPB2 and αB-crystallin genes located in a head-to-head manner

HSPB2 和 αB-晶状体蛋白基因的表达以头对头的方式定位

基本信息

批准号：
10680654
负责人：
IWAKI Akiko
金额：
$ 1.92万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10680654/
关键词：
Heat shock protein Crystallin Stress ストレス蛋白質クリスタン

项目摘要

Previously we identified a new member of the α-crystallin/small heat shock protein (HSP) family and named it HSPB2 (Genomics, 1997). The HSPB2 gene and the αB-crystallin gene, another member of the small HSP family, are arranged in a head-to-head manner with an intergenic sequence of 956 bp, raising a possibility of shared enhancer elements for their expression. In this study we examined spatial and temporal expression patterns of the newly identified HSPB2 gene and compared with that of the αB-crystallin gene. Furthermore, we investigated the regulatory mechanisms of expression of the two genes in cultured cells and transgenic mice. (1) Northern blotting and in situ hybridization revealed that the HSPB2 gene is expressed in heart and muscles but not in eye lens. Although the level of HSPB2 mRNA was much lower than that of αB-crystallin, the developmental profiles of their expression were similar in muscles (in preparation). (2) Functional promoter analysis of the two genes in C2C12 cells and transgenic mice revealed a competition of muscle specific enhancer elements, which arc present in the intergenic region (in preparation). (3) αB-Crystallin, but not HSPB2, accumulates in glial cells in response to high extracellular potassium concentrations. Functional promoter analysis using deletion and mutation constructs revealed that the heat shock element (HSE) is essential for transcriptional activation of the αB-crystallin gene by KCl in U-251MG.Gel mobility shift and antibody supershift assays showed that KCl induces the HSE-binding activity of heat shock factor 2 (HSF2), suggesting that HSF2 is involved in KCl-depedent increases in αB-crystallin mRNA in glial cells (submitted).

以前，我们确定了α-晶状蛋白/小热休克蛋白（HSP）家族的新成员，并将其命名为HSPB2（Genomics，1997）。 HSPB2基因和小型HSP家族的另一个成员的αB-晶状体基因以956 bp的基因间序列的正面方式排列，从而提高了共享增强子元素以表达其表达的可能性。在这项研究中，我们检查了新鉴定的HSPB2基因的空间和临时表达模式，并将其与αB-晶状体基因的空间表达模式进行了比较。此外，我们研究了培养细胞和转基因小鼠中两个基因表达的调节机制。（1）北印迹和原位杂交表明，HSPB2基因在心脏和肌肉中表达，但在眼镜镜片中不表达。尽管HSPB2 mRNA的水平远低于αB-晶状体蛋白的水平，但其表达的发育特征在肌肉中相似（在制备中）。（2）对C2C12细胞和转基因小鼠中两个基因的功能启动子分析揭示了肌肉特异性增强子元素的竞争，该元素构成了基因间区域（制备中）中存在的竞争。（3）αB-晶状体蛋白，而不是HSPB2，响应高细胞外钾浓度而在神经胶质细胞中积聚。使用缺失和突变构建体的功能启动子分析表明，He Heach元件（HSE）对于在U-251MG.GEL迁移率转移和抗体supershift测定中对αB-晶状体基因的转录激活至关重要。神经胶质细胞中的αB-晶状体mRNA（提交）。