Amino acid substitution converts WEREWOLF function from an activator to a repressor of Arabidopsis non-hair cell development
Amino acid substitution converts WEREWOLF function from an activator to a repressor of Arabidopsis non-hair cell development
复制标题
氨基酸取代将 WEREWOLF 功能从拟南芥非毛细胞发育的激活剂转变为抑制剂
DOI：
10.1016/j.plantsci.2011.11.001
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发表时间：
2012
期刊：
影响因子：
5.2
通讯作者：
Rumi Tominaga-Wada
中科院分区：
文献类型：
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作者：
R. Tominaga-Wada;Y. Nukumizu;T. Wada;Rumi Tominaga-Wada;Rumi Tominaga-Wada;Rumi Tominaga-Wada;Rumi Tominaga-Wada;Rumi Tominaga-Wada;Rumi Tominaga-Wada
拟南芥根表皮毛细胞或非毛细胞命运的决定是植物细胞发育的模式系统。两种类型的MYB转录因子，R2 R3型MYB，WEREWOLF（WER）和R3型MYB，CAPRICE（CPC），参与了这一细胞命运决定过程。为了研究这一过程的分子基础，我们分析了WER和CPC的功能关系。WER-CPC嵌合构建体由WER制成，其中MYB R3区的全部或部分被来自CPC R3的相应区域替换，并且将构建体引入cpc-2突变体中。虽然WER基因不能拯救CPC-2突变体的“少量根毛”表型，但具有两个氨基酸取代的WER-CPC嵌合体（WC 6）完全拯救了CPC-2突变体表型。此外，WER-CPC嵌合体与37个氨基酸的取代（WC 5）过度拯救CPC-2突变体，并诱导比野生型多2.5倍的根毛。与这种表型一致，在CPC-2背景下，GL 2基因表达在WC 5中强烈降低。我们的结果表明，交换至少两个氨基酸就足以将WER转换为CPC功能。因此，这些关键残基可能对这些重要功能的进化选择有很大贡献。
Root hair cell or non-hair cell fate determination in Arabidopsis thaliana root epidermis is model system for plant cell development. Two types of MYB transcription factors, the R2R3-type MYB, WEREWOLF (WER), and an R3-type MYB, CAPRICE (CPC), are involved in this cell fate determination process. To study the molecular basis of this process, we analyzed the functional relationship of WER and CPC. WER–CPC chimeric constructs were made from WER where all or parts of the MYB R3 region were replaced with the corresponding regions from CPC R3, and the constructs were introduced into the cpc-2 mutant. Although, the WER gene did not rescue the cpc-2 mutant ‘small number of root hairs’ phenotype, the WER–CPC chimera with two amino acids substitution (WC6) completely rescued the cpc-2 mutant phenotype. Furthermore, the WER–CPC chimera with 37 amino acids substitution (WC5) excessively rescued the cpc-2 mutant and induced 2.5 times more root hairs than wild-type. Consistent with this phenotype, GL2 gene expression was strongly reduced in WC5 in a cpc-2 background. Our results suggest that swapping at least two amino acids is sufficient to convert WER to CPC function. Therefore, these key residues may have strongly contributed to the selection of these important functions over evolution.