Transceptor NRT1.1 and Receptor-Kinase QSK1 Complex Controls PM H -ATPase Activity Under Low Nitrate

• DOI: 10.2139/ssrn.4593630
• Publication Date: 2023-10-06T16:31:43Z
• Authors: Zhe Zhu; Leonard Krall; Zhi Li; Lin Xi; Hongxiu Luo; Shalan Li; Mingjie He; Xiaolin Yang; Haitao Zan; Max Gilbert; Sven Gombos; Ting Wang; Benjamin Neuhäuser; Aurore Jacquot; Laurence Lejay; Jingbo Zhang; Junzhong Liu; Waltraud X. Schulze; Xu Na Wu

NRT1.1, a nitrate transceptor, plays an important role in binding, sensing and dependent lateral root (LR) morphology. However, little is known about NRT1.1-mediated signaling transduction through plasma membrane (PM)-localized proteins. Through in-depth phosphoproteome profiling using membranes of Arabidopsis roots, we identified receptor kinase QSK1 H+-ATPase AHA2 as potential downstream components NRT1.1 mild low (LN)-dependent manner. QSK1, functional molecular link, physically interacts with at LN, specifically phosphorylates S899. Importantly, found that not HN, induces formation NRT1.1-QSK1-AHA2 complex order to repress the proton efflux into apoplast by increased phosphorylation Loss either or thus results higher T947/S899 ratio on AHA2, leading enhanced pump activity longer LRs under LN. Our uncover regulatory mechanism which LN conditions, recruits coreceptor transduce PM controlling activating inhibitory sites AHA2. This then altered activity, acidification, regulation LR growth.