Research Information System
2nd Japan – Turkey International Symposium on Pharmaceutical and Biomedical Sciences (JATUSPAB-2), Trabzon, Turkey, 11 - 12 September 2017, pp.22
Objective / Purpose:
NON-EXPRESSOR OF PATHOGENESIS-RELATED GENE1(NPR1) of Arabidopsis thaliana is responsible for the trafficking around 50 physical interactions in cells. Beyond, it is a key regulator of salicylic acid(SA)-mediated gene expression in systemic acquired resistance(SAR) ad further controls the cross-talk between SA and jasmonate(JA). Although the vital regulatory roles of NPR1 protein; its 3 dimensional(3D) structure was not identified yet. Elucidating the 3D structure of NPR1 is highly crucial to unravel its regulatory functions towards diverse metabolic responses such as SAR, ubiquitination, JA, and such. The interaction of NPR1 with Thioredoxin h5 (TRX5) protein, playing a key role in redox signalling and oxidative stress responses, was also examined.
Material and Methods:
3D prediction of NPR1 and TRXh5 proteins were performed through I-TASSER. The modelled structures were then refined using 3DRefine[1]. To identify and locate the crucial residues, domains on the 3D structures, Simple Modular Architecture Research Tool(SMART) and InterPro analyses were performed on protein sequence(593) of NPR1. Root mean square fluctuations(RMSF) of NPR1 protein was also identified through DynOmics analysis. To identify the binding pocket of TRXh5 on NPR1 protein, Clus2Pro and Patchdock analyses were comparatively performed.
Results:
NPR1 protein harbors a α-solenoid class 3D structure. NPR1 contains 3 domains with various functions; BTB/POZ, ankryin and C-terminal nuclear localization sequence. RMSF analysis revealed that N and C termini of NPR1 are more dynamic. NPR1 and TRXh5 docking studies revelaed that through residues between 124-178, TRXh5 directly interacts with NPR1 for reduction of C150 residue overlapping onto POZ domain responsible for DNA binding[2]. C150 reduction is critical for SA responsive PR1 gene transactivation.
Conclusion / Discussion:
Here we report first time modeling the 3D structure of NPR1, regulatory defense response protein in plants. The insights into NPR1 3D structure will enlighten the further understanding of other complex regulatory mechanisms and crosstalk among various regulatory immune response pathways.