Plant cysteine oxidases are dioxygenases that directly enable arginyl transferase-catalysed arginylation of N-end rule targets.
Plant cysteine oxidases are dioxygenases that directly enable arginyl transferase-catalysed arginylation of N-end rule targets.
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DOI：
10.1038/ncomms14690
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发表时间：
2017-03-23
影响因子：
16.6
通讯作者：
Flashman E
中科院分区：
文献类型：
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作者：
White MD;Klecker M;Hopkinson RJ;Weits DA;Mueller C;Naumann C;O'Neill R;Wickens J;Yang J;Brooks-Bartlett JC;Garman EF;Grossmann TN;Dissmeyer N;Flashman E
洪水造成的作物减产对粮食安全构成威胁。植物在水下缺氧导致第七族乙烯反应因子（erf -VII）的稳定，这有助于在这些不利条件下生存。ERF-VII的稳定性受n端规则通路控制，这表明ERF-VII n端半胱氨酸氧化在常氧环境下可使精氨酸化，然后是蛋白酶体降解。植物半胱氨酸氧化酶（PCOs）已被确定为这种氧化的催化剂。缺氧时ERF-VII的稳定可能是由于PCO活性降低所致。我们直接证明，PCO双加氧酶活性在ERF-VII肽的N端产生半胱氨酸亚磺酸，然后由精氨酸转移酶（ATE1）进行有效的精氨酸化。这为植物中n端规则通路组分和ATE1底物形成n端半胱氨酸和精氨酸化提供了分子证据。PCOs和ATE1可能是稳定n端规则底物（包括erf - vii）以提高农业耐淹性的可行干预靶点。n端规则途径针对蛋白酶体降解的底物蛋白。在这里，White等人表明拟南芥植物半胱氨酸氧化酶具有双加氧酶活性，在靶蛋白的n端产生半胱氨酸亚磺酸，然后作为精氨酸转移酶的直接底物。
Crop yield loss due to flooding is a threat to food security. Submergence-induced hypoxia in plants results in stabilization of group VII ETHYLENE RESPONSE FACTORs (ERF-VIIs), which aid survival under these adverse conditions. ERF-VII stability is controlled by the N-end rule pathway, which proposes that ERF-VII N-terminal cysteine oxidation in normoxia enables arginylation followed by proteasomal degradation. The PLANT CYSTEINE OXIDASEs (PCOs) have been identified as catalysts of this oxidation. ERF-VII stabilization in hypoxia presumably arises from reduced PCO activity. We directly demonstrate that PCO dioxygenase activity produces Cys-sulfinic acid at the N terminus of an ERF-VII peptide, which then undergoes efficient arginylation by an arginyl transferase (ATE1). This provides molecular evidence of N-terminal Cys-sulfinic acid formation and arginylation by N-end rule pathway components, and a substrate of ATE1 in plants. The PCOs and ATE1 may be viable intervention targets to stabilize N-end rule substrates, including ERF-VIIs, to enhance submergence tolerance in agriculture. The N-end rule pathway targets substrate proteins for proteasomal degradation. Here, White et al. show that Arabidopsis PLANT CYSTEINE OXIDASEs show dioxygenase activity producing Cys-sulfinic acid at the N-terminus of target proteins, which then act as direct substrates for arginyl transferase.