Molecular basis for the selective and ABA-independent inhibition of PP2CA by PYL13
Molecular basis for the selective and ABA-independent inhibition of PP2CA by PYL13
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DOI：
10.1038/cr.2013.143
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发表时间：
2013-12-01
期刊：
影响因子：
44.1
通讯作者：
Yan, Nieng
中科院分区：
文献类型：
--
作者：
Li, Wenqi;Wang, Li;Yan, Nieng
PYR 1/PYL/RCAR家族蛋白（PYLs）是已充分表征的脱落酸（阿坝）受体。在拟南芥的14个PYL成员中，PYL 13是阿坝不敏感的，其功能仍然是未知的。在这里，我们表明，PYL 13选择性地抑制PP 2CA的磷酸酶活性的阿坝的独立。在2.4埃分辨率下测定的PYL 13-PP 2CA复合物的晶体结构阐明了PP 2CA和PYL 13之间特异性识别的分子基础。除了典型的PYL和PP 2Cs之间的相互作用，一个额外的接口被确定涉及一个以前未表征的CCCH锌指（ZF）基序在PP 2CA附近的元素。测序blast鉴定了另外56个含ZF的PP 2C，它们都来自植物。该结构还揭示了PYL 13的阿坝不响应性的分子决定因素。最后，生化分析表明PYL 13可能与PYL 10异源寡聚化。这两种PYL在其各自的ABA-独立的PP 2Cs抑制中相互拮抗。PYL 13的生物化学和结构研究为深入了解PYL 13在植物逆境胁迫反应中的功能提供了重要的信息，并为PYL 13的生物技术应用奠定了基础。
PYR1/PYL/RCAR family proteins (PYLs) are well-characterized abscisic acid (ABA) receptors. Among the 14 PYL members in Arabidopsis thaliana, PYL13 is ABA irresponsive and its function has remained elusive. Here, we show that PYL13 selectively inhibits the phosphatase activity of PP2CA independent of ABA. The crystal structure of PYL13-PP2CA complex, which was determined at 2.4 angstrom resolution, elucidates the molecular basis for the specific recognition between PP2CA and PYL13. In addition to the canonical interactions between PYLs and PP2Cs, an extra interface is identified involving an element in the vicinity of a previously uncharacterized CCCH zinc-finger (ZF) motif in PP2CA. Sequence blast identified another 56 ZF-containing PP2Cs, all of which are from plants. The structure also reveals the molecular determinants for the ABA irresponsiveness of PYL13. Finally, biochemical analysis suggests that PYL13 may hetero-oligomerize with PYL10. These two PYLs antagonize each other in their respective ABA-independent inhibitions of PP2Cs. The biochemical and structural studies provide important insights into the function of PYL13 in the stress response of plant and set up a foundation for future biotechnological applications of PYL13.