| Structural highlights
Function
P2C16_ARATH Key component and repressor of the abscisic acid (ABA) signaling pathway that regulates numerous ABA responses, such as stomatal closure, seed germination and inhibition of vegetative growth. Confers enhanced sensitivity to drought.[1] [2] [3] [4]
Publication Abstract from PubMed
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.
The Molecular Basis of ABA-Independent Inhibition of PP2Cs by a Subclass of PYL Proteins.,Hao Q, Yin P, Li W, Wang L, Yan C, Lin Z, Wu JZ, Wang J, Yan SF, Yan N Mol Cell. 2011 Jun 10;42(5):662-72. PMID:21658606[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Saez A, Apostolova N, Gonzalez-Guzman M, Gonzalez-Garcia MP, Nicolas C, Lorenzo O, Rodriguez PL. Gain-of-function and loss-of-function phenotypes of the protein phosphatase 2C HAB1 reveal its role as a negative regulator of abscisic acid signalling. Plant J. 2004 Feb;37(3):354-69. PMID:14731256
- ↑ Robert N, Merlot S, N'guyen V, Boisson-Dernier A, Schroeder JI. A hypermorphic mutation in the protein phosphatase 2C HAB1 strongly affects ABA signaling in Arabidopsis. FEBS Lett. 2006 Aug 21;580(19):4691-6. Epub 2006 Jul 24. PMID:16876791 doi:10.1016/j.febslet.2006.07.047
- ↑ Saez A, Robert N, Maktabi MH, Schroeder JI, Serrano R, Rodriguez PL. Enhancement of abscisic acid sensitivity and reduction of water consumption in Arabidopsis by combined inactivation of the protein phosphatases type 2C ABI1 and HAB1. Plant Physiol. 2006 Aug;141(4):1389-99. Epub 2006 Jun 23. PMID:16798945 doi:10.1104/pp.106.081018
- ↑ Saez A, Rodrigues A, Santiago J, Rubio S, Rodriguez PL. HAB1-SWI3B interaction reveals a link between abscisic acid signaling and putative SWI/SNF chromatin-remodeling complexes in Arabidopsis. Plant Cell. 2008 Nov;20(11):2972-88. doi: 10.1105/tpc.107.056705. Epub 2008 Nov, 25. PMID:19033529 doi:10.1105/tpc.107.056705
- ↑ Hao Q, Yin P, Li W, Wang L, Yan C, Lin Z, Wu JZ, Wang J, Yan SF, Yan N. The Molecular Basis of ABA-Independent Inhibition of PP2Cs by a Subclass of PYL Proteins. Mol Cell. 2011 Jun 10;42(5):662-72. PMID:21658606 doi:10.1016/j.molcel.2011.05.011
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