Since its discovery in the late 1970s, the ubiquitin proteasome pathway appears to be omnipresent in many research fields. Although originally discovered in animals, the pathway has a very central role in plants, whic...Since its discovery in the late 1970s, the ubiquitin proteasome pathway appears to be omnipresent in many research fields. Although originally discovered in animals, the pathway has a very central role in plants, which may be correlated to their sessile lifestyle. E3 ligases function as flexible and highly diverse key regulators within the path- way by targeting substrate proteins for ubiquitylation, and often proteolytic degradation via the 26S proteasome. This review provides a concise overview on the most common classes of E3 ligases so far described in plants, and emphasizes recent findings regarding these interesting and flexible enzymes and their diverse functions in plant biology.展开更多
基金This work was supported by the National Science Foundation （NSF grant MCB-1020673 to H.H.）,We would like to thank Sutton Mooney for critical reading and NSF for support （NSF grant MCB-1020673 to H.H.）. No conflict of interest declared.
文摘Since its discovery in the late 1970s, the ubiquitin proteasome pathway appears to be omnipresent in many research fields. Although originally discovered in animals, the pathway has a very central role in plants, which may be correlated to their sessile lifestyle. E3 ligases function as flexible and highly diverse key regulators within the path- way by targeting substrate proteins for ubiquitylation, and often proteolytic degradation via the 26S proteasome. This review provides a concise overview on the most common classes of E3 ligases so far described in plants, and emphasizes recent findings regarding these interesting and flexible enzymes and their diverse functions in plant biology.
文摘目的观察肾衰养真胶囊对慢性肾衰竭(chronic renal failure,CRF)营养不良大鼠泛素蛋白酶体通路(ubiquitin proteasome pathway,UPP)的影响。方法采用5/6肾切除同时予4%酪蛋白饮食制备CRF营养不良大鼠模型。40只SD大鼠按体重随机分为假手术组、模型组、肾衰养真胶囊组和开同组,每组10只。术后1周肾衰养真胶囊组给予每天肾衰养真胶囊0.28 g/mL灌胃,开同组给予开同片每天0.21 g/mL灌胃,同时模型组予等体积的生理盐水灌胃,假手术组不施加任何干预,持续干预4周。检测肌酐(SCr)、尿素氮(BUN)、24 h尿蛋白(24 h Upro)、白蛋白(Alb)、血红蛋白(Hb)水平,应用免疫组化检测骨骼肌泛素(Ub)蛋白表达,免疫荧光检测骨骼肌肌肉萎缩蛋白(MAFbx)和肌环指蛋白-1(MuRF-1)蛋白表达。结果与假手术组比较,模型组SCr、BUN、24 h Upro水平升高,Alb、Hb水平下降,骨骼肌Ub、MAFbx、MuRF-1蛋白表达水平升高(P<0.01)。与模型组比较,开同组和肾衰养真胶囊组SCr、BUN水平下降,Alb水平升高,Ub、MAFbx、MuRF-1蛋白表达水平下降(P<0.05,P<0.01);肾衰养真胶囊组24 h Upro水平下降,Hb水平升高(P<0.01)。与开同组比较,肾衰养真胶囊组24 h Upro水平下降,BUN、Hb 7水平升高更明显(P<0.05,P<0.01),开同组MAFbx蛋白表达水平较肾衰养真胶囊组下降更明显(P<0.01)。结论肾衰养真胶囊可能通过减少骨骼肌Ub、MAFbx和MuRF-1蛋白表达,从而抑制UPP信号通路的活性,减少蛋白分解,改善CRF营养不良。
