Dephosphorylation of CatC at Ser-18 improves salt and oxidative tolerance via promoting its tetramerization in rice
Dephosphorylation of CatC at Ser-18 improves salt and oxidative tolerance via promoting its tetramerization in rice
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DOI：
10.1016/j.plantsci.2023.111597
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发表时间：
2023-01-23
期刊：
影响因子：
5.2
通讯作者：
Liu, Xuanming
中科院分区：
文献类型：
--
作者：
Wang, Yan;Yi, Yuting;Liu, Xuanming
过氧化氢酶（CAT）是一种重要的抗氧化酶，而磷酸化是其功能的关键。在CAT中已经鉴定出许多磷酸化位点，但它们的功能在很大程度上仍然是难以捉摸的。我们对水稻CatC基因的5个磷酸丝氨酸（Ser-9、-10、-11、-18和-205）进行了功能研究。磷酸化Ser-9和-11和脱磷酸化Ser-18促进CatC的酶活性，并增强酵母的耐氧化性和耐盐性。Ser-18的磷酸化状态不影响CatC过氧化物酶体的靶向和稳定性，但脱磷酸Ser-18促进CatC四聚化以增强其活性。此外，在水稻中过量表达脱磷酸模拟形式CatCS 18 A通过抑制H2 O2积累显著提高了对盐和氧化胁迫的耐受性。这些结果阐明了Ser-18去磷酸化促进水稻CatC活性和耐盐性的机制。Ser-18是一个很有希望用于培育高耐盐水稻的CatC候选磷酸化位点。
Catalase (CAT) is a vital antioxidant enzyme, while phosphorylation pivotally regulates its function. Many phosphosites have been identified in CAT, but their functions remained largely elusive. We functionally studied five phosphoserines (Ser-9,-10,-11,-18, and-205) of CatC in rice (Oryza sativa L.). Phospho-Ser-9 and -11 and dephospho-Ser-18 promoted the enzymatic activity of CatC and enhanced oxidative and salt tolerance in yeast. Phosphorylation status of Ser-18 did not affect CatC peroxisomal targeting and stability, but dephospho-Ser-18 promoted CatC tetramerization to enhance its activity. Moreover, overexpression of dephospho-mimic form CatCS18A in rice significantly improved the tolerance to salt and oxidative stresses by inhibiting the H2O2 accumulation. Together, these results elucidate the mechanism underlying dephosphorylation at Ser-18 pro-motes CatC activity and salt tolerance in rice. Ser-18 is a promising candidate phosphosite of CatC for breeding highly salt-tolerant rice.