Oral Presentation 2014 International Biophysics Congress

PYL10 modulation by ABA through structure stabilization (#138)

Juan Li 1 , Chaowei Shi , Fangming Wu 2 , Changlin Tian 1 2
  1. University of Science and Technology of China, Hefei, China
  2. High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, China

PYL10 is a special member of ABA receptor family, inhibiting protein phosphatase 2C (PP2C) activity as a monomer, different from the other dimeric ABA receptors. Previous studies of PYL10 from Arabidopsis thaliana reported that the PP2C phosphatase inhibition activity of PYL10 was ABA independent. Here, systematic biochemical assays of PYL10 showed that the extra addition of the reaction condition such as bovine serum albumin (BSA) could affect the PP2C phosphatase inhibition activity. Indicating that PYL10 may have another way to execute its function. Furthermore, backbone residue assignments of PYL10 in the presence of ABA were accomplished using solution nuclear magnetic resonance(NMR). Backbone relaxation experiments and chemical shift perturbation studies of apo- and ABA-PYL10 lead to a hypothesis that ABA binding to PYL10 stabilizes the receptor’s structure, providing a basis for further PP2C phosphatase inhibition activity of PYL10. At the same time, solution NMR titration of PYL10 with increased ABA concentration illustrated three different dynamics responses by residues of PYL10.