Doukhanina Elena V, Chen Shaorong, van der Zalm Esther, Godzik Adam, Reed John, Dickman Martin B
Department of Plant Pathology, University of Nebraska, Lincoln, Nebraska 68583, USA.
J Biol Chem. 2006 Jul 7;281(27):18793-801. doi: 10.1074/jbc.M511794200. Epub 2006 Apr 24.
The genes that control mammalian programmed cell death are conserved across wide evolutionary distances. Although plant cells can undergo apoptosis-like cell death, plant homologs of mammalian regulators of apoptosis have, in general, not been found. This is in part due to the lack of primary sequence conservation between animal and putative plant regulators of apoptosis. Thus, alternative approaches beyond sequence similarities are required to find functional plant homologs of apoptosis regulators. Here, we present the results of using advanced bioinformatic tools to uncover the Arabidopsis family of BAG proteins. The mammalian BAG (Bcl-2-associated athanogene) proteins are a family of chaperone regulators that modulate a number of diverse processes ranging from proliferation to growth arrest and cell death. Such proteins are distinguished by a conserved BAG domain that directly interacts with Hsp70 and Hsc70 proteins to regulate their activity. Our searches of the Arabidopsis thaliana genome sequence revealed seven homologs of the BAG protein family. We further show that plant BAG family members are also multifunctional and remarkably similar to their animal counterparts, as they regulate apoptosis-like processes ranging from pathogen attack to abiotic stress and development.
控制哺乳动物程序性细胞死亡的基因在广泛的进化距离中都是保守的。虽然植物细胞可以经历类似凋亡的细胞死亡，但一般来说，尚未发现哺乳动物凋亡调节因子的植物同源物。部分原因是动物和假定的植物凋亡调节因子之间缺乏一级序列保守性。因此，需要序列相似性之外的其他方法来寻找凋亡调节因子的功能性植物同源物。在这里，我们展示了使用先进的生物信息学工具来揭示拟南芥BAG蛋白家族的结果。哺乳动物的BAG（Bcl-2相关抗凋亡基因）蛋白是一类伴侣调节因子家族，可调节从增殖到生长停滞和细胞死亡等多种不同过程。这类蛋白的特点是有一个保守的BAG结构域，它直接与Hsp70和Hsc70蛋白相互作用以调节它们的活性。我们对拟南芥基因组序列的搜索揭示了BAG蛋白家族的七个同源物。我们进一步表明，植物BAG家族成员也是多功能的，并且与它们的动物对应物非常相似，因为它们调节从病原体攻击到非生物胁迫和发育等类似凋亡的过程。
