Structural elements of the ubiquitin-independent proteasome degron of ornithine decarboxylase.
Structural elements of the ubiquitin-independent proteasome degron of ornithine decarboxylase.
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鸟氨酸脱羧酶的不依赖于泛素的蛋白酶体降解决定子的结构元件。
DOI：
10.1042/bj20071239
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
Coffino,Philip
中科院分区：
文献类型：
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作者：
Takeuchi,Junko;Chen,Hui;Hoyt,MartinA;Coffino,Philip
小鼠ODC(鸟氨酸脱羧酶)在哺乳动物和真菌细胞中被26S蛋白酶体迅速降解。它的降解独立于泛素，但需要一个由ODC C末端425-461残基组成的降解信号，cODC(ODC C末端的最后37个氨基酸)。对cODC的突变分析表明，降解信号中存在两个基本成分。第一种由半胱氨酸和丙氨酸组成，分别位于第441和442位残基。第二个元件是残基442远端的C-末端；它几乎没有或没有序列特异性，但不能容忍改变其跨度的插入或缺失。还原条件排除了Cys441硫醇的所有特征良好的化学反应，这对体外降解是必不可少的。这些实验表明，Cys441的降解功能不涉及其参与化学反应；相反，它在26S蛋白酶体识别的结构元件中发挥作用。
Mouse ODC (ornithine decarboxylase) is quickly degraded by the 26S proteasome in mammalian and fungal cells. Its degradation is independent of ubiquitin but requires a degradation signal composed of residues 425–461 at the ODC C-terminus, cODC (the last 37 amino acids of the ODC C-terminus). Mutational analysis of cODC revealed the presence of two essential elements in the degradation signal. The first consists of cysteine and alanine at residues 441 and 442 respectively. The second element is the C-terminus distal to residue 442; it has little or no sequence specificity, but is intolerant of insertions or deletions that alter its span. Reducing conditions, which preclude all well-characterized chemical reactions of the Cys441thiol, are essential forin vitrodegradation. These experiments imply that the degradative function of Cys441does not involve its participation in chemical reaction; it, instead, functions within a structural element for recognition by the 26S proteasome.