植物响应低磷胁迫的蛋白质泛素化途径研究进展

Advances in protein ubiquitination in response to low phosphorus stress in plants

磷是构成许多关键性大分子的重要底物,在植物体内许多生理生化反应中都发挥着重要作用,磷供应不足会极大地限制作物的产量和品质。在漫长的进化过程中,植物形成了一系列适应低磷胁迫的机制,其中,蛋白质水平的泛素化修饰对植物响应低磷胁迫起重要作用。泛素化修饰可以改变靶蛋白的活性、稳定性及其在亚细胞的定位等。对关键蛋白的泛素化修饰在植物低磷胁迫响应中的调控功能和机制进行归类总结,综述植物蛋白质泛素化途径调控低磷胁迫的研究进展。蛋白质泛素化修饰研究主要从泛素、酶和靶蛋白3个组分方面进行。泛素由76个氨基酸组成,并以逐步共轭级联的方式与靶蛋白相连,形成泛素–蛋白质复合体,该复合体被运输至26S蛋白酶体内消化与降解,从而调控众多生理过程。蛋白质泛素化修饰通过改变根系形态构型,影响磷转运子和转录因子的活性和定位,从而促进或抑制植物对土壤磷的吸收以及向地上部的运输,进而调节磷稳态。最后,提出了对植物响应低磷胁迫的蛋白质泛素化需要进行的研究。

Phosphorus(P)serves as important substrates of many key macromolecules,and plays important roles in many physiological regulatory reactions in plants.Inefficient phosphorous nutrition has been one of the main factors limiting crop yield and quality.In the long-term evolution process,plants have evolved a series of mechanisms to adapt to low P stress.Protein ubiquitination has been found as an important path in plant responses to low P stress recently.In this paper,the roles and mechanisms of ubiquitination of key proteins in response to P deficiency in plants were summarized,and the recent advances on plant ubiquitination approach to cope with P starvation were reviewed.Protein ubiquitination can change the activity,stability and subcellular localization of the target proteins.Ubiquitin,enzyme and target protein are three main components involved in ubiquitin modification.Ubiquitin is composed of 76 amino acids,which are linked to the target protein in a step-by-step conjugate cascade,forming an ubiquitin protein complex,which is transported to 26S proteasome for degradation in vivo to regulate many different physiological processes.Protein ubiquitin modification can promote or inhibit the uptake of P in soils,and its transport to the shoot by changing the root architecture through hormone signaling pathway,affecting the activity and localization of phosphate transporters and related transcription factors,thus regulating P homeostasis.In the end,the research focus of protein ubiquitination in response to low P stress in future is prospected.