INHIBITION OF UBIQUITIN-DEPENDENT PROTEOLYSIS BY DES-GLY-GLY-UBIQUITIN - IMPLICATIONS FOR THE MECHANISM OF POLYUBIQUITIN SYNTHESIS
INHIBITION OF UBIQUITIN-DEPENDENT PROTEOLYSIS BY DES-GLY-GLY-UBIQUITIN - IMPLICATIONS FOR THE MECHANISM OF POLYUBIQUITIN SYNTHESIS
复制标题
DOI：
10.1016/0006-291x(89)91966-9
复制
发表时间：
1989-07-14
影响因子：
3.1
通讯作者：
BRESLOW, E
中科院分区：
文献类型：
--
作者：
BAMEZAI, S;TATE, S;BRESLOW, E
从天然泛素中切割两个羧基末端的甘氨酸残基，得到不能蛋白质降解的衍生物DES-Gly-Gly-Ubiquitin。我们在这里报道，这种衍生物抑制酪蛋白依赖于ATP的降解，并且是多种泛素化的，但不被网织红细胞裂解物降解。对蛋白质降解的抑制作用随天然泛素浓度的增加而减弱，但不随酪蛋白浓度的增加而降低。切割泛素的最后四个残基产生了一种衍生物，它对蛋白质降解的抑制作用较弱，对泛素化的底物较差。这些结果表明，在多泛素合成过程中，泛素与泛素的结合涉及到一个特定的结合系统，该系统识别泛素及其一些衍生物，而不是一般的蛋白降解底物，作为泛素的受体。
Cleavage of the two carboxyl-terminal glycine residues from native ubiquitin yields the proteolysis-incompetent derivative des-Gly-Gly-ubiquitin. We report here that this derivative inhibits the ATP-dependent degradation of casein and is multi-ubiquitinated but not degraded by reticulocyte lysates. Inhibition of proteolysis diminished with increasing concentration of native ubiquitin, but was not reduced by increased casein concentration. Cleavage of the last four residues from ubiquitin yielded a derivative that was a weaker inhibitor of proteolysis and a poorer substrate for ubiquitination. These results suggest that the conjugation of ubiquitin to ubiquitin during polyubiquitin synthesis involves a specific conjugation system that recognizes ubiquitin and some of its derivatives, but not general proteolysis substrates, as ubiquitin acceptors.