Regulatory function of PP2C phosphatases in plant ion homeostasis

PP2C磷酸酶在植物离子稳态中的调节功能

• 批准号: 220972194
• 负责人: Dr. Benjamin Neuhäuser
• 金额: --
• 依托单位: Fachgebiet Ernährungsphysiologie der Kulturpflanzen (340h)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/220972194?language=en
• 关键词: Regulatory; function; PP2C; phosphatases; plant

Ammonium is an ubiquitous key nutrient in agricultural soils that is taken up by microorganisms and plants via high-affinity transporters of the ammonium transporter / rhesus glycoprotein (AMT/Rh) family. The precise localization of each AMT member and the transcriptional, post-transcriptional and post-translational regulation contribute to the adequate ammonium nutrition. In Arabidopsis thalina, six AMT genes are identified, which separate in two distinct clades (AMT1 and AMT2) and code for transporters with distinct functional properties. Current knowledge suggests that the activity of individual AMTs is regulated in a complex, complementary manner. An allosteric switch by phosphorylation at the C-terminus has been identified that regulates the activity of AMT1s. The phosphorylation of a conserved threonine in the AMT carboxyl-terminus inactivates the transport of the AMT1 trimer. This phosphorylation is directly ammonium dependent and increases rapidly after ammonium resupply. Preliminary work in the frame of the project "Plant ammonium transporter (AMT) integration in regulatory Networks" identified CIPK23 as AMT1 phosphorylating and regulating kinase. The results further identified two PP2C phosphatases as potential regulators of AMT1 transporters. The complex AMT1 regulation cascade as a whole is not completely decoded yet. It is still unclear if and in which way the identified PP2Cs might act in this cascade. These candidates will therefore be characterized in this project. The results will yield a better comprehension of the molecular basis of NH4+, K+ and NO3- ion homeostasis in plants.

铵是农业土壤中普遍存在的关键养分，微生物和植物通过铵转运体/恒河糖蛋白（AMT/Rh）家族的高亲和力转运体吸收铵。每个AMT成员的精确定位以及转录、转录后和翻译后的调控有助于获得充足的铵营养。在拟南芥中，已鉴定出6个AMT基因，它们在两个不同的分支（AMT1和AMT2）中分离，并编码具有不同功能特性的转运蛋白。目前的知识表明，单个amt的活性以一种复杂的、互补的方式受到调节。通过在c端磷酸化的变构开关已被确定调节AMT1s的活性。AMT羧基端保守苏氨酸的磷酸化使AMT1三聚体的转运失活。这种磷酸化直接依赖于铵，并在铵补给后迅速增加。在“植物铵转运体（AMT）在调控网络中的整合”项目框架下的初步工作确定了CIPK23是AMT1磷酸化和调控激酶。结果进一步确定了两种PP2C磷酸酶作为AMT1转运蛋白的潜在调节因子。复杂的AMT1调控级联作为一个整体尚未完全解码。目前尚不清楚这些已确定的pp2c是否以及以何种方式在这种级联反应中起作用。因此，这些候选人将在本项目中进行特征描述。该结果将有助于更好地理解植物NH4+、K+和NO3-离子动态平衡的分子基础。

项目成果

Electrophysiological characterization of AtAMT1;4, an extraordinarily high affinity ammonium transporter from Arabidopsis thaliana

• DOI: 10.1101/820712
• 发表时间: 2019-10
• 期刊: bioRxiv
• 作者: Nino Bindel;B. Neuhäuser

Distinct transport mechanism in Candida albicans methylammonium permeases

• DOI: 10.1007/s11557-020-01625-0
• 发表时间: 2020-10
• 期刊: Mycological Progress
• 影响因子: 2.4
• 作者: B. Neuhäuser

A twin histidine motif is the core structure for high-affinity substrate selection in plant ammonium transporters

• DOI: 10.1074/jbc.ra119.010891
• 发表时间: 2020-03-06
• 期刊: JOURNAL OF BIOLOGICAL CHEMISTRY
• 影响因子: 4.8
• 作者: Ganz, Pascal;Ijato, Toyosi;Neuhaeuser, Benjamin
• 通讯作者: Neuhaeuser, Benjamin

Abscisic-acid-dependent regulation of Arabidopsis thaliana ammonium transport relies on ABI1 control of CIPK23 and AMT1

• DOI: 10.1101/2021.02.09.430435
• 发表时间: 2021-02
• 期刊: bioRxiv
• 作者: P. Ganz;Romano Porras-Murillo;Toyosi Ijato;Jochen Menz;Tatsiana Straub;Nils Stührwohldt;Narges Moradtalab;U. Ludewig;B. Neuhäuser

Small proteins modulate ion channel-like ACD6 to regulate immunity in Arabidopsis thaliana

• DOI: 10.1101/2021.01.25.428077
• 发表时间: 2021-01
• 期刊: bioRxiv
• 作者: Junbin Chen;Lei Li;Jong Hum Kim;B. Neuhäuser;Mingyu Wang;M. Thelen;Richard Hilleary;Yuan Chi;Luyang Wei;Kavita Venkataramani;Moisés Expósito-Alonso;Chang Liu;J. Keck;A. C. Barragan;R. Schwab;Ulrich Lutz;Zhen-Ming Pei;S. He;U. Ludewig;D. Weigel;Wangsheng Zhu