权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Assembly and sorting mechanisms of CCAAT-box binding complex of filamentous fungi

丝状真菌CCAAT-box结合复合物的组装和分选机制

基本信息

批准号：
16580057
负责人：
KATO Masashi
金额：
$ 2.43万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16580057/
关键词：
filamentous fungi Aspergillus oryzae CCAAT Hap assembly nuclear import sorting NF-Y タカアミラーゼA 転写因子

项目摘要

One of the transcription factors of filamentous fungi, CCAAT-box binding factor, is widely conserved among eukaryotes, which consist of three subunits HapB, and C and E. The following results were obtained in this research.1. The order of the assembly of CCAAT-box binding complex subunits was determined.2. All three Hap subunits were expressed as a GFP-fusion protein in the hap deletion strains, respectively. Observation of the localization of the GFP-fusion proteins revealed that nuclear localization of HapC and HapE requires the other two subunits, respectively, while nuclear translocation of HapB was independent on HapC and HapE.3. Analysis on the nuclear localization signal of HapB revealed that there are two redundant nuclear localization signals in the conserved core region and non-conserved C-terminal region.4. It was found that HapE is easy to become an insoluble form by itself. Addition of HapC prior to the in vitro synthesis of HapE significantly increases the solubility of HapE. Taken together with the facts that HapE and HapC possess the histone-fold motif and form a hetero-dimer, it was suggested that HapC may act as a chaperon-like factor specific to HapE to prevent the insolublilization of HapE.In this research, we have elucidated the mechanism of the assembly-dependent nuclear localization of the filamentous fungal CCAAT-box binding factor which universally exists in eukaryotes, prior to researches with other eukaryotic organisms. Furthermore, we have also elucidated the molecule mechanism of the stabilization of the HapE by HapC, which is a potential molecular basis for the quantity control mechanisms of the subunits of the CCAAT-binding complex.

丝状真菌的转录因子之一CCAAT-box结合因子在真核生物中广泛保守，由HapB、C、E三个亚基组成。本研究获得以下结果： 1．确定了CCAAT-box结合复合物亚基的组装顺序。 2．所有三个 Hap 亚基分别在 hap 缺失菌株中表达为 GFP 融合蛋白。对GFP融合蛋白定位的观察表明，HapC和HapE的核定位分别需要另外两个亚基，而HapB的核转位不依赖于HapC和HapE。3。对HapB的核定位信号进行分析发现，在保守的核心区和非保守的C端区域存在两个冗余的核定位信号。 4．发现HapE本身很容易变成不溶形式。在体外合成 HapE 之前添加 HapC 可显着增加 HapE 的溶解度。结合HapE和HapC具有组蛋白折叠基序并形成异源二聚体的事实，表明HapC可能作为HapE特异的类伴侣因子来阻止HapE的不溶化。在本研究中，我们阐明了普遍存在于丝状真菌CCAAT-box结合因子的组装依赖性核定位机制。真核生物，先于其他真核生物的研究。此外，我们还阐明了HapC稳定HapE的分子机制，这为CCAAT结合复合物亚基的数量控制机制提供了潜在的分子基础。