| 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]
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[4]
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
- ↑ 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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