| Structural highlights
Function
[PYR1_ARATH] Receptor for abscisic acid (ABA) required for ABA-mediated responses such as stomatal closure and germination inhibition. Inhibits the activity of group-A protein phosphatases type 2C (PP2Cs) when activated by ABA.[1] [2] [3] [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.[4] [5] [6] [7]
Publication Abstract from PubMed
Abscisic acid (ABA) is a key hormone regulating plant growth, development and the response to biotic and abiotic stress. ABA binding to pyrabactin resistance (PYR)/PYR1-like (PYL)/Regulatory Component of Abscisic acid Receptor (RCAR) intracellular receptors promotes the formation of stable complexes with certain protein phosphatases type 2C (PP2Cs), leading to the activation of ABA signalling. The PYR/PYL/RCAR family contains 14 genes in Arabidopsis and is currently the largest plant hormone receptor family known; however, it is unclear what functional differentiation exists among receptors. Here, we identify two distinct classes of receptors, dimeric and monomeric, with different intrinsic affinities for ABA and whose differential properties are determined by the oligomeric state of their apo forms. Moreover, we find a residue in PYR1, H60, that is variable between family members and plays a key role in determining oligomeric state. In silico modelling of the ABA activation pathway reveals that monomeric receptors have a competitive advantage for binding to ABA and PP2Cs. This work illustrates how receptor oligomerization can modulate hormonal responses and more generally, the sensitivity of a ligand-dependent signalling system.
A thermodynamic switch modulates abscisic acid receptor sensitivity.,Dupeux F, Santiago J, Betz K, Twycross J, Park SY, Rodriguez L, Gonzalez-Guzman M, Jensen MR, Krasnogor N, Blackledge M, Holdsworth M, Cutler SR, Rodriguez PL, Marquez JA EMBO J. 2011 Aug 16;30(20):4171-84. doi: 10.1038/emboj.2011.294. PMID:21847091[8]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Santiago J, Rodrigues A, Saez A, Rubio S, Antoni R, Dupeux F, Park SY, Marquez JA, Cutler SR, Rodriguez PL. Modulation of drought resistance by the abscisic acid receptor PYL5 through inhibition of clade A PP2Cs. Plant J. 2009 Nov;60(4):575-88. doi: 10.1111/j.1365-313X.2009.03981.x. Epub 2009 , Jul 16. PMID:19624469 doi:10.1111/j.1365-313X.2009.03981.x
- ↑ Park SY, Fung P, Nishimura N, Jensen DR, Fujii H, Zhao Y, Lumba S, Santiago J, Rodrigues A, Chow TF, Alfred SE, Bonetta D, Finkelstein R, Provart NJ, Desveaux D, Rodriguez PL, McCourt P, Zhu JK, Schroeder JI, Volkman BF, Cutler SR. Abscisic acid inhibits type 2C protein phosphatases via the PYR/PYL family of START proteins. Science. 2009 May 22;324(5930):1068-71. doi: 10.1126/science.1173041. Epub 2009, Apr 30. PMID:19407142 doi:10.1126/science.1173041
- ↑ Szostkiewicz I, Richter K, Kepka M, Demmel S, Ma Y, Korte A, Assaad FF, Christmann A, Grill E. Closely related receptor complexes differ in their ABA selectivity and sensitivity. Plant J. 2010 Jan;61(1):25-35. doi: 10.1111/j.1365-313X.2009.04025.x. Epub 2009, Sep 21. PMID:19769575 doi:10.1111/j.1365-313X.2009.04025.x
- ↑ 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
- ↑ Dupeux F, Santiago J, Betz K, Twycross J, Park SY, Rodriguez L, Gonzalez-Guzman M, Jensen MR, Krasnogor N, Blackledge M, Holdsworth M, Cutler SR, Rodriguez PL, Marquez JA. A thermodynamic switch modulates abscisic acid receptor sensitivity. EMBO J. 2011 Aug 16;30(20):4171-84. doi: 10.1038/emboj.2011.294. PMID:21847091 doi:10.1038/emboj.2011.294
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