State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 163 Xianlin Ave, Nanjing, 210046, China.
BMC Mol Cell Biol. 2021 Jan 28;22(1):9. doi: 10.1186/s12860-021-00344-y.
Leucine-rich-repeat receptor-like kinases (LRR-RLKs) play central roles in sensing various signals to regulate plant development and environmental responses. The extracellular domains (ECDs) of plant LRR-RLKs contain LRR motifs, consisting of highly conserved residues and variable residues, and are responsible for ligand perception as a receptor or co-receptor. However, there are few comprehensive studies on the ECDs of LRR-RLKs due to the difficulty in effectively identifying the divergent LRR repeats.
In the current study, an efficient LRR motif prediction program, the "Phyto-LRR prediction" program, was developed based on the position-specific scoring matrix algorithm (PSSM) with some optimizations. This program was trained by 16-residue plant-specific LRR-highly conserved segments (HCS) from LRR-RLKs of 17 represented land plant species and a database containing more than 55,000 predicted LRRs based on this program was constructed. Both the prediction tool and database are freely available at http://phytolrr.com/ for website usage and at http://github.com/phytolrr for local usage. The LRR-RLKs were classified into 18 subgroups (SGs) according to the maximum-likelihood phylogenetic analysis of kinase domains (KDs) of the sequences. Based on the database and the SGs, the characteristics of the LRR motifs in the ECDs of the LRR-RLKs were examined, such as the arrangement of the LRRs, the solvent accessibility, the variable residues, and the N-glycosylation sites, revealing a comprehensive profile of the plant LRR-RLK ectodomains.
The "Phyto-LRR prediction" program is effective in predicting the LRR segments in plant LRR-RLKs, which, together with the database, will facilitate the exploration of plant LRR-RLKs functions. Based on the database, comprehensive sequential characteristics of the plant LRR-RLK ectodomains were profiled and analyzed.
富含亮氨酸重复序列的受体样激酶(LRR-RLKs)在感知各种信号以调节植物发育和环境响应方面发挥着核心作用。植物 LRR-RLK 的细胞外结构域(ECDs)包含 LRR 基序,由高度保守残基和可变残基组成,负责作为受体或共受体感知配体。然而,由于有效识别分歧 LRR 重复序列的困难,对 LRR-RLK 的 ECDs 进行的综合研究较少。
在本研究中,基于位置特异性评分矩阵算法(PSSM)并进行了一些优化,开发了一种有效的 LRR 基序预测程序,即“Phyto-LRR prediction”程序。该程序由来自 17 种代表性陆地植物物种的 LRR-RLK 的 16 残基植物特异性 LRR 高度保守片段(HCS)和基于该程序构建的包含超过 55000 个预测 LRR 的数据库进行训练。预测工具和数据库均可在 http://phytolrr.com/ 网站上免费使用,也可在 http://github.com/phytolrr 上本地使用。根据序列的激酶结构域(KDs)的最大似然系统发育分析,将 LRR-RLK 分为 18 个亚组(SGs)。基于数据库和 SGs,检查了 LRR-RLKs ECDs 中 LRR 基序的特征,如 LRR 的排列、溶剂可及性、可变残基和 N-糖基化位点,揭示了植物 LRR-RLK 胞外结构域的综合特征。
“Phyto-LRR prediction”程序可有效预测植物 LRR-RLK 中的 LRR 片段,该程序与数据库一起将有助于探索植物 LRR-RLK 的功能。基于数据库,对植物 LRR-RLK 胞外结构域的综合序列特征进行了分析和分析。