Cell Research Online Reported New Discovery by Prof. Hongwei Guo’s Group at Biology Department

Research

| 06/06/2016

On May 27th, the research groups of Prof. Hongwei Guo from Biology Department at SUSTech and Prof. Jijie Chai at Tsinghua University published their joint research paper entitled “Signature motif-guided identification of receptors for peptide hormones essential for root meristem growth” on Cell Research Online. The paper reportedon the discovery of five receptor kinases (RGFRs) as the receptors, and SERKs as the co-receptors, for plant peptide hormone root meristem growth factors (RGFs). This work revealing the molecular mechanism of RGF signaling perception by RGFRs and providing a proof of principle for structure-based matching peptide-receptor pairs in plants.

A Discovery of RGFRs and molecular mechanism of RGFs recognition by RGFRs .

B Essential function of RGFRs for RAM development.

C RGF induced dimerization and activation of RGFR and SERK co-receptors during RAM development regulation.

Root system is the major plant organ for absorbing moisture and nutrient from soil, therefor its root growth largely affects the growth and development of the whole plant organism. A recent study reported that a family of secreted and tyrosine sulfated small peptides RGFs are important for stem cell niche maintenance and root pattern formation by defining the expression and distribution of the transcription factors PLETHORAs (PLTs). In plant, LRR-RK family is the largest subfamily of receptor-like kinase (RLK). It is widely studied because some members in this family were identified as signal receptors. Despite the important roles of RGFs in plant development, their receptors remain unidentified, because the redundancy of the receptors largely renders genetic screening difficulty.

Hongwei Guo’s group and Jijie Chai’s group applied an in vitro biochemical assay to identify the receptors of RGFs. Based on a signature small peptide recognition motif (RxR) conserved in a subfamily of LRR-RKs, they screened a pool of small peptides for their abilities to interact with the extracellular LRR domains of LRR-RKs from this subfamily. By this assay, they identified a functionally uncharacterized RK as the receptor of RGF1 (RGFR1), which was supported by a combination of biochemical, structural and genetic evidence. Additional four RGFRs were further identified based on a second structural motif, RxGG, which is responsible for specific recognition of the sulfate group of RGF1 as revealed by the crystal structure of the RGF1-RGFR1 complex. They also proved that SERKs function as co-receptors for RGFs. Identification of the receptors and co-receptors of RGFs provide new insight into RAM regulation and will facilitate further dissection of RGF-induced signaling pathways. Furthermore, the screening strategy described in the paper can be used to match RGF-like peptide ligands with their receptors in plants.

Wen Song (PhD student) from Tsinghua University and Li Liu (PhD student) from Peking University are co-first authors; Prof. Jijie Chai, Prof. Hongwei Guo and Dr. Zhifu Han are co-corresponding authors of the paper; Jizong Wang, Zhen Wu, Heqiao Zhang, Jiao Tang and Guangzhong Lin from Tsinghua University, Yichuan Wang, Xing Wen and Wenyang Li from Peking University also participated in part of the work. This research was funded by State Key Program of National Natural Science of China and Peking University -Tsinghua University Center for Life Sciences.

The paper links: http://www.nature.com/cr/journal/v26/n6/full/cr201662a.html

2016, 06-06