The Molecular Basis of ABA-Independent Inhibition of PP2Cs by a Subclass of PYL Proteins

Qi Hao, Ping Yin, Wenqi Li, Li Wang, Chuangye Yan, Zhaohu Lin, Jim Zhen Wu, Jiawei Wang, S. Frank Yan, Nieng Yan

Research output: Contribution to journalArticlepeer-review

214 Scopus citations


PYR1/PYL/RCAR proteins (PYLs) are confirmed abscisic acid (ABA) receptors, which inhibit protein phosphatase 2C (PP2C) upon binding to ABA. Arabidopsis thaliana has 14 PYLs, yet their functional distinction remains unclear. Here, we report systematic biochemical characterization of PYLs. A subclass of PYLs, represented by PYL10, inhibited PP2C in the absence of any ligand. Crystal structures of PYL10, both in the free form and in the HAB1 (PP2C)-bound state, revealed the structural basis for its constitutive activity. Structural-guided biochemical analyses revealed that ABA-independent inhibition of PP2C requires the PYLs to exist in a monomeric state. In addition, the residues guarding the entrance to the ligand-binding pocket of these PYLs should be bulky and hydrophobic. Based on these principles, we were able to generate monomeric PYL2 variants that gained constitutive inhibitory effect on PP2Cs. These findings provide an important framework for understanding the complex regulation of ABA signaling by PYL proteins.

Original languageEnglish (US)
Pages (from-to)662-672
Number of pages11
JournalMolecular Cell
Issue number5
StatePublished - Jun 10 2011

All Science Journal Classification (ASJC) codes

  • Molecular Biology
  • Cell Biology


Dive into the research topics of 'The Molecular Basis of ABA-Independent Inhibition of PP2Cs by a Subclass of PYL Proteins'. Together they form a unique fingerprint.

Cite this