关键词: E3连接酶；亚细胞定位；表达谱分析；组织特异性

Abstract:

Ubiquitination pathway plays important roles in plant responses to biotic and abiotic stress, especially E3 plays decisive role in pathway of ubiquitin ligases. 2 Arabidopsis RING domain protein At2g24480(HHR1) and At5g43200(HHR2) were found, which were related to abiotic stress, through prediction of gene chip online. In vitro selfubiquitination assay demonstrated that the 2 RING domain proteins possess an E3 ligase activity. In this paper, subcellular localization, gene expression profiles, tissue specificity of them were conducted. We found that they showed differences in subcellular localization, gene expression profiles, tissue specificity. HHR1 was positioned on cell membrane, while HHR2 in nucleus. Our studies demonstrated that both HHR1 and HHR2 were related to H2O2 stress. In addition, HHR1 and HHR2 were related to heat and salt stress, respectively. The analysis of expressional pattern revealed that HHR1 was highly expressed in root and flower, less expressed in leaves and stems. However, HHR2 relatively expressed less in flower, but highly expressed in roots, stems and leaves. These results confirmed that certain properties and subcellular localization of HHR1 and HHR2, and laid foundation for further studies on their function.

Key words: E3 ubiquitin ligases, subcellular localization, gene expression profile, tissue specificity