| 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
In Arabidopsis, signaling of the stress hormone abscisic acid (ABA) is mediated by PYR/PYL/RCAR receptors (PYLs), which bind to and inhibit group-A protein phosphatases 2C (PP2Cs), the negative regulators of ABA. X-ray structures of several PYL-ABA and PYL-ABA-PP2C complexes have revealed that a conserved tryptophan in PP2Cs is inserted into a small tunnel adjacent to the C4' of ABA in the PYL-ABA complex and plays a crucial role in the formation and stabilization of the PYL-ABA-PP2C complex. Here, 4'-modified ABA analogues were designed to prevent the insertion of the tryptophan into the tunnel adjacent to the C4' of ABA in these complexes. These analogues were predicted to block PYL-PP2C receptor interactions and thus block ABA signaling. To test this, 4'- O-phenylpropynyl ABA analogues were synthesized as novel PYL antagonists (PANs). Structural, thermodynamic, biochemical, and physiological studies demonstrated that PANs completely abolished ABA-induced PYL-PP2C interactions in vitro and suppressed stress-induced ABA responses in vivo more strongly than did 3'-hexylsulfanyl-ABA (AS6), a PYL antagonist we developed previously. The PANs and AS6 antagonized the effects of ABA to different degrees in different plants, suggesting that these PANs can function as chemical scalpels to dissect the complicated regulatory mechanism of ABA signaling in plants.
Structure-Based Chemical Design of Abscisic Acid Antagonists That Block PYL-PP2C Receptor Interactions.,Takeuchi J, Mimura N, Okamoto M, Yajima S, Sue M, Akiyama T, Monda K, Iba K, Ohnishi T, Todoroki Y ACS Chem Biol. 2018 Apr 11. doi: 10.1021/acschembio.8b00105. PMID:29620349[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
- ↑ Takeuchi J, Mimura N, Okamoto M, Yajima S, Sue M, Akiyama T, Monda K, Iba K, Ohnishi T, Todoroki Y. Structure-Based Chemical Design of Abscisic Acid Antagonists That Block PYL-PP2C Receptor Interactions. ACS Chem Biol. 2018 Apr 11. doi: 10.1021/acschembio.8b00105. PMID:29620349 doi:http://dx.doi.org/10.1021/acschembio.8b00105
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