Abstract:
Trichome patterning in Arabidopsis is regulated by R2R3MYB, bHLH and WDR (MBW) genes. These are considered to form a trimeric MBW protein complex that promotes trichome formation. The MBW proteins are engaged in a regulatory network to select trichome cells among epidermal cells through R3MYB proteins that can move between cells and repress the MBW complex by competitive binding with the R2R3MYB to the bHLHL protein. We use quantitative pull-down assays to determine the relative dissociation constants for the protein-protein interactions of the involved genes. We find similar binding strength between the trichome promoting genes and weaker binding of the R3MYB inhibitors. We used the dissociation constants to calculate the relative percentage of all possible complex combinations and found surprisingly low fractions of those complexes that are typically considered to be relevant for the regulation events. Finally, we predict an increased robustness in patterning as a consequence of higher ordered complexes mediated by GL3 dimerization.
摘要:
拟南芥中的毛状体模式受R2R3MYB调控,bHLH和WDR(MBW)基因。这些被认为形成促进毛状体形成的三聚体MBW蛋白复合物。MBW蛋白参与调节网络,通过R3MYB蛋白在表皮细胞中选择毛状体细胞,R3MYB蛋白可以在细胞之间移动并通过与R2R3MYB竞争性结合bHLHL蛋白来抑制MBW复合物。我们使用定量下拉测定法来确定相关基因的蛋白质-蛋白质相互作用的相对解离常数。我们发现毛状体促进基因和R3MYB抑制剂的较弱结合之间的结合强度相似。我们使用解离常数来计算所有可能的复合物组合的相对百分比,并且令人惊讶地发现通常被认为与调节事件相关的那些复合物的分数低。最后,我们预测,由于GL3二聚化介导的更高有序的复合物,图案形成的鲁棒性增加。