植物U-box蛋白研究进展

Recent Advances in Study for Plant U-box Proteins

U-box结构是真核生物体内尤其是植物中广泛存在的一种高度保守的基序,其构象与RING-finger极其相似,两者都能发挥泛素连接酶E3的作用,促进底物蛋白泛素化降解。U-box基序还是泛素链聚集酶E4最主要的功能因子。在植物体内U-box经常与ARM重复耦联形成U-box/ARM结构,影响蛋白-蛋白互作,参与信号传导级联反应。许多植物U-box蛋白(PUB)能有效提高植株对干旱、高盐、异常温度等非生物胁迫的抵抗能力。此外,在植物对许多病原物的抗病反应中也需要U-box蛋白的参与。

U - box domain was a high conserved motif existing widely in eukaryotes, especially in plants. The domain of U - box was similar to that of the RING - finger. Both U - box motif and RING - finger could function as uhiquitin - ligase E3 to catalyze the target proteins ubiquitinated degradation. The U - box motif also was the main functional factor of ubiqnitin chain assembly enzyme FA. In plant, U - box usually conjugates with ARM repeats to form the U - box/ARM repeats structure which involved in protein - protein interactions and signal transduction cascade reactions. Many plant U - box proteins could efficiently enhance plants defense to abiotic stresses such as drought, high salinity and abnormal temperature. In addition, U -box proteins were required in plants resistante response to pathogens.