Proteasome inhibitors prevent tracheary element differentiation in Zinnia mesophyll cell cultures
Proteasome inhibitors prevent tracheary element differentiation in Zinnia mesophyll cell cultures
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DOI：
10.1104/pp.118.2.419
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发表时间：
1998-10-01
期刊：
影响因子：
7.4
通讯作者：
Beers, EP
中科院分区：
文献类型：
--
作者：
Woffenden, BJ;Freeman, TB;Beers, EP
为了确定蛋白酶体活性是否需要的导管元件（TE）的分化，蛋白酶体抑制剂断裂-lactacystin β-内酯和carbenzoxy-leucinyl-leucinyl-leucinal（LLL）中使用的百日菊（Zinnia elegans）叶肉细胞培养系统。在培养开始时加入蛋白酶体抑制剂阻止了分化，否则在96小时可检测到。与对照组相比，在细胞分化后48小时抑制蛋白酶体并没有改变TE的最终百分比。然而，蛋白酶体抑制在48小时延迟了分化过程约24小时，这两个形态标志物和推定的自溶蛋白酶的表达检查所示。这些结果表明，蛋白酶体的功能是必需的诱导TE分化和TE程序在定向细胞的进展。在48小时用LLL而不是裂乳胞素β-内酯处理导致自溶与分化的部分解偶联。蛋白酶活性的凝胶分析结果表明，所观察到的不完全自溶是由于LLL抑制TE半胱氨酸蛋白酶的能力。
To determine whether proteasome activity is required for tracheary element (TE) differentiation, the proteasome inhibitors clasto-lactacystin beta-lactone and carbobenzoxy-leucinyl-leucinyl-leucinal (LLL) were used in a zinnia (Zinnia elegans) mesophyll cell culture system. The addition of proteasome inhibitors at the time of culture initiation prevented differentiation otherwise detectable at 96 h. Inhibition of the proteasome at 48 h, after cellular commitment to differentiation, did not alter the final percentage of TEs compared with controls. However, proteasome inhibition at 48 h delayed the differentiation process by approximately 24 h, as indicated by examination of both morphological markers and the expression of putative autolytic proteases. These results indicate that proteasome function is required both for induction of TE differentiation and for progression of the TE program in committed cells. Treatment at 48 h with LLL but not clasto-lactacystin beta-lactone resulted in partial uncoupling of autolysis from differentiation. Results from gel analysis of protease activity suggested that the observed incomplete autolysis was due to the ability of LLL to inhibit TE cysteine proteases.