Desmethyl butenolides are optimal ligands for karrikin receptor proteins
Desmethyl butenolides are optimal ligands for karrikin receptor proteins
复制标题
去甲基丁烯内酯是 karrikin 受体蛋白的最佳配体
DOI：
10.1111/nph.17224
复制
发表时间：
2021
期刊：
影响因子：
9.4
通讯作者：
Waters, Mark T.
中科院分区：
文献类型：
--
作者：
Yao, Jiaren;Scaffidi, Adrian;Meng, Yongjie;Melville, Kim T.;Komatsu, Aino;Khosla, Aashima;Nelson, David C.;Kyozuka, Junko;Flematti, Gavin R.;Waters, Mark T.
独脚金内酯和karrikins是调节植物生长的丁烯酰亚胺分子。它们分别被α/β水解酶DWARF 14（D14）及其同源物KARRIKIN INSENSITIVE 2（KAI 2）感知。植物来源的独脚金内酯具有一个带有甲基的丁烯内酯环，这对生物活性至关重要。相比之下，卡里金是非生物来源的，丁烯基甲基是非必需的。KAI 2可能是一种内源性丁烯酰亚胺的受体，但这种化合物的身份仍然未知。在这里，我们使用遗传和生物化学方法研究了KAI 2对不同丁烯酰亚胺配体的特异性。我们发现，来自多个物种的KAI 2蛋白对缺乏甲基的去甲基丁烯内酯最敏感。去甲基-GR 24和去甲基-CN-地Branone通过KAI 2而不是D14具有活性。与其甲基取代的参比化合物相比，它们是更有效的KAI 2激动剂，无论是在体外还是在植物中。KAI 2对去甲基丁烯内酯的选择性在卷柏和地钱中是保守的，这表明它是陆生植物进化中的一个古老性状.我们的研究结果为KAI 2和D14对配体的不同感知提供了机制基础，并支持KAI 2和D14的内源底物具有不同的化学结构和生物合成来源的观点.
Strigolactones and karrikins are butenolide molecules that regulate plant growth. They are perceived by the α/β‐hydrolase DWARF14 (D14) and its homologue KARRIKIN INSENSITIVE2 (KAI2), respectively. Plant‐derived strigolactones have a butenolide ring with a methyl group that is essential for bioactivity. By contrast, karrikins are abiotic in origin, and the butenolide methyl group is nonessential. KAI2 is probably a receptor for an endogenous butenolide, but the identity of this compound remains unknown.Here we characterise the specificity of KAI2 towards differing butenolide ligands using genetic and biochemical approaches.We find that KAI2 proteins from multiple species are most sensitive to desmethyl butenolides that lack a methyl group. Desmethyl‐GR24 and desmethyl‐CN‐debranone are active by KAI2 but not D14. They are more potent KAI2 agonists compared with their methyl‐substituted reference compounds bothin vitroand in plants. The preference of KAI2 for desmethyl butenolides is conserved inSelaginella moellendorffiiandMarchantia polymorpha, suggesting that it is an ancient trait in land plant evolution.Our findings provide insight into the mechanistic basis for differential ligand perception by KAI2 and D14, and support the view that the endogenous substrates for KAI2 and D14 have distinct chemical structures and biosynthetic origins.