Chen Quanqing, Zhao Tian, Song Hao, Sha Siyuan, Ma Jun, Zhang Ruihan, Kong Weiwen, Yang Shuying, Liu Jinglan, Wang Yiping
College of Plant Protection, Yangzhou University, Yangzhou 225009, China.
Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China.
Plants (Basel). 2025 Jun 12;14(12):1801. doi: 10.3390/plants14121801.
Plant U-box (PUB) E3 ubiquitin ligases have undergone significant expansion compared to their fungal and animal counterparts. These E3 ligases play critical roles in diverse biological processes, including responses to biotic and abiotic stresses. However, systematic identification of genes in cucumber ( L.) has been lacking, and their expression and functional characterization remain largely unexplored. Leveraging the recently released near-complete cucumber genome, we identified 53 putative PUB proteins classified into eight distinct groups based on domain architecture. The molecular weights of CsPUBs range from 26 to 166 kilodaltons (kDa). Exon numbers in genes vary substantially, with containing a maximum of 17 exons, while 18 genes harbor only a single exon. Chromosomal distribution of is uneven, with Chr 3 harboring the highest density (12 genes) and Chr 7 the lowest (1 gene). Notably, tandem duplications (e.g., - and -) and seven collinear gene pairs were identified, suggesting evolutionary diversification. Promoter regions of are enriched with -regulatory elements linked to plant growth and development, phytohormone, stress responses, light, and so on, implying their regulatory roles in various biological processes. Expression profiling revealed tissue-specific patterns and differential regulation of multiple under stress conditions. Subcellular localization studies demonstrated that CsPUBs target diverse organelles, with some localizing to punctate structures potentially representing uncharacterized compartments. Collectively, this systematic analysis establishes a comprehensive framework for understanding particular CsPUB functions.
与真菌和动物中的同类相比，植物U-box（PUB）E3泛素连接酶经历了显著的扩张。这些E3连接酶在多种生物学过程中发挥关键作用，包括对生物和非生物胁迫的响应。然而，黄瓜（Cucumis sativus L.）中基因的系统鉴定一直缺乏，其表达和功能特征在很大程度上仍未得到探索。利用最近发布的近乎完整的黄瓜基因组，我们鉴定出53个假定的PUB蛋白，根据结构域结构将其分为八个不同的组。黄瓜PUB蛋白的分子量范围为26至166千道尔顿（kDa）。CsPUB基因中的外显子数量差异很大，其中CsPUB17包含最多17个外显子，而18个CsPUB基因仅含有一个外显子。CsPUB基因的染色体分布不均匀，3号染色体上的密度最高（12个基因），7号染色体上的密度最低（1个基因）。值得注意的是，鉴定出了串联重复（例如CsPUB11 - CsPUB12和CsPUB25 - CsPUB26）和七对共线基因对，表明其进化多样化。CsPUB基因的启动子区域富含与植物生长发育、植物激素、胁迫响应、光照等相关的顺式作用元件，这意味着它们在各种生物学过程中发挥调节作用。表达谱分析揭示了组织特异性模式以及多种CsPUB在胁迫条件下的差异调节。亚细胞定位研究表明，CsPUB蛋白靶向多种细胞器，其中一些定位于点状结构，可能代表未鉴定的区室。总的来说，这种系统分析为理解特定的CsPUB功能建立了一个全面的框架。
