Carbonic Anhydrases Function in Anther Cell Differentiation Downstream of the Receptor-Like Kinase EMS1
Carbonic Anhydrases Function in Anther Cell Differentiation Downstream of the Receptor-Like Kinase EMS1
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DOI：
10.1105/tpc.16.00484
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发表时间：
2017-06-01
期刊：
影响因子：
11.6
通讯作者：
Zhao, Dazhong
中科院分区：
文献类型：
--
作者：
Huang, Jian;Li, Zhiyong;Zhao, Dazhong
植物广泛使用富含亮氨酸的重复受体样激酶（LRR-RLKs）作为最大的RLKs家族，控制着广泛的生长发育过程以及防御反应。迄今为止，仅确定了少数lrr - rlk的直接下游效应物。我们之前的研究表明，在拟南芥花药发育早期，LRR-RLK EMS1 （EXCESS MICROSPOROCYTES1）及其配体TPD1 （TAPETUM DETERMINANT1）是体细胞绒毡层细胞和生殖小孢子细胞分化所必需的。在这里，我们报道了β -碳酸酐酶（β - CAs）作为EMS1的直接下游靶点的鉴定。EMS1与β - CA蛋白发生生物化学相互作用。β - CA基因功能缺失导致绒毡层细胞分化缺陷，而β - CA1过表达导致绒毡层外细胞形成。EMS1在四个位点磷酸化β - CA1，导致β - CA1活性增加。此外，磷酸化阻断突变破坏了β - CA1在绒毡层细胞分化中的功能；然而，磷酸化模拟突变促进绒毡层细胞的形成。- CAs也参与绒毡层细胞的pH调节。我们的研究结果强调了β - CA在控制细胞分化中的作用，并提供了通过受体样激酶介导的磷酸化对碳酸酐酶的翻译后修饰的见解。
Plants extensively employ leucine-rich repeat receptor-like kinases (LRR-RLKs), the largest family of RLKs, to control a wide range of growth and developmental processes as well as defense responses. To date, only a few direct downstream effectors for LRR-RLKs have been identified. We previously showed that the LRR-RLK EMS1 (EXCESS MICROSPOROCYTES1) and its ligand TPD1 (TAPETUM DETERMINANT1) are required for the differentiation of somatic tapetal cells and reproductive microsporocytes during early anther development in Arabidopsis thaliana. Here, we report the identification of beta-carbonic anhydrases (beta CAs) as the direct downstream targets of EMS1. EMS1 biochemically interacts with beta CA proteins. Loss of function of beta CA genes caused defective tapetal cell differentiation, while overexpression of beta CA1 led to the formation of extra tapetal cells. EMS1 phosphorylates beta CA1 at four sites, resulting in increased beta CA1 activity. Furthermore, phosphorylation-blocking mutations impaired the function of beta CA1 in tapetal cell differentiation; however, a phosphorylation mimic mutation promoted the formation of tapetal cells. beta CAs are also involved in pH regulation in tapetal cells. Our findings highlight the role of beta CA in controlling cell differentiation and provide insights into the posttranslational modification of carbonic anhydrases via receptor-like kinase-mediated phosphorylation.