Rajan Vinoth Babu V, D'Silva Patrick
Biochemistry Department, Indian Institute of Science, Bangalore, India.
Funct Integr Genomics. 2009 Nov;9(4):433-46. doi: 10.1007/s10142-009-0132-0. Epub 2009 Jul 25.
Plants are sessile organisms that have evolved a variety of mechanisms to maintain their cellular homeostasis under stressful environmental conditions. Survival of plants under abiotic stress conditions requires specialized group of heat shock protein machinery, belonging to Hsp70:J-protein family. These heat shock proteins are most ubiquitous types of chaperone machineries involved in diverse cellular processes including protein folding, translocation across cell membranes, and protein degradation. They play a crucial role in maintaining the protein homeostasis by reestablishing functional native conformations under environmental stress conditions, thus providing protection to the cell. J-proteins are co-chaperones of Hsp70 machine, which play a critical role by stimulating Hsp70s ATPase activity, thereby stabilizing its interaction with client proteins. Using genome-wide analysis of Arabidopsis thaliana, here we have outlined identification and systematic classification of J-protein co-chaperones which are key regulators of Hsp70s function. In comparison with Saccharomyces cerevisiae model system, a comprehensive domain structural organization, cellular localization, and functional diversity of A. thaliana J-proteins have also been summarized.
植物是固着生物，它们已经进化出多种机制，以便在压力环境条件下维持细胞内稳态。植物在非生物胁迫条件下的存活需要属于Hsp70:J蛋白家族的一组特殊的热休克蛋白机制。这些热休克蛋白是最普遍存在的伴侣机制类型，参与包括蛋白质折叠、跨细胞膜转运和蛋白质降解在内的多种细胞过程。它们通过在环境胁迫条件下重新建立功能性天然构象来维持蛋白质稳态，从而为细胞提供保护。J蛋白是Hsp70机制的共伴侣，通过刺激Hsp70的ATP酶活性发挥关键作用，从而稳定其与客户蛋白的相互作用。通过对拟南芥的全基因组分析，我们在此概述了作为Hsp70功能关键调节因子的J蛋白共伴侣的鉴定和系统分类。与酿酒酵母模型系统相比，还总结了拟南芥J蛋白的全面结构域组织、细胞定位和功能多样性。
