OsHYPK-mediated protein N-terminal acetylation coordinates plant development and abiotic stress responses in rice
OsHYPK-mediated protein N-terminal acetylation coordinates plant development and abiotic stress responses in rice
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DOI：
10.1016/j.molp.2022.03.001
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发表时间：
2022-04-06
期刊：
影响因子：
27.5
通讯作者：
Wang, Yonghong
中科院分区：
文献类型：
--
作者：
Gong, Xiaodi;Huang, Yaqian;Wang, Yonghong
N-末端乙酰化是真核生物中最常见的蛋白质修饰之一，大约40%的人和植物蛋白质组被核糖体相关的N-末端乙酰基转移酶A(NatA)以共翻译的方式乙酰化。然而，NatA的体内调控机制以及NatA介导的N-末端乙酰化对蛋白质命运的全球影响仍不清楚。在这里，我们确定亨廷顿酵母伴侣K(HYPK)是一种进化上保守的伴侣样蛋白，是水稻中NatA活性的正调控因子。我们发现，OsHYPK功能的丧失导致水稻植株结构的发育缺陷，但增加了对非生物胁迫的抗性，这可归因于N-末端乙酰基组的扰动和全球蛋白质的加速周转。此外，我们还证明了OsHYPK也是NatA的底物，并且OsHYPK的N-末端乙酰化可能通过非生物胁迫诱导的Ac/N-degron途径促进自身的降解。综上所述，我们的研究结果表明，OsHYPK-NatA复合体通过动态调节NatA介导的N-末端乙酰化和全球蛋白质周转，在协调植物发育和逆境反应中发挥关键作用，这是维持水稻适应性表型可塑性所必需的。
N-terminal acetylation is one of the most common protein modifications in eukaryotes, and approxi-mately 40% of human and plant proteomes are acetylated by ribosome-associated N-terminal acetyl-transferase A (NatA) in a co-translational manner. However, the in vivo regulatory mechanism of NatA and the global impact of NatA-mediated N-terminal acetylation on protein fate remain unclear. Here, we identify Huntingtin Yeast partner K (HYPK), an evolutionarily conserved chaperone-like protein, as a positive regulator of NatA activity in rice. We found that loss of OsHYPK function leads to develop-mental defects in rice plant architecture but increased resistance to abiotic stresses, attributable to perturbation of the N-terminal acetylome and accelerated global protein turnover. Furthermore, we demonstrated that OsHYPK is also a substrate of NatA and that N-terminal acetylation of OsHYPK pro-motes its own degradation, probably through the Ac/N-degron pathway, which could be induced by abiotic stresses. Taken together, our findings suggest that the OsHYPK-NatA complex plays a critical role in coordinating plant development and stress responses by dynamically regulating NatA-mediated N-terminal acetylation and global protein turnover, which are essential for maintaining adaptive pheno-typic plasticity in rice.