The hPLIC proteins may provide a link between the ubiquitination machinery and the proteasome
The hPLIC proteins may provide a link between the ubiquitination machinery and the proteasome
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DOI：
10.1016/s1097-2765(00)00040-x
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发表时间：
2000-08-01
期刊：
影响因子：
16
通讯作者：
Howley, PM
中科院分区：
文献类型：
--
作者：
Kleijnen, MF;Shih, AH;Howley, PM
尽管泛素化机制与降解底物上的多泛素链存在结合位点，但目前尚不清楚在体内泛素化机制和蛋白酶体的活性是否偶联。在这里，我们发现酵母泛素样Dsk2蛋白的两个人类同源物，hPLIC-1和hPLIC-2，在大的复合体中与蛋白酶体和泛素连接酶物理上相关。HPLIC蛋白的过表达干扰了两种不相关的泛素依赖的蛋白酶体底物P53和I kappa Bα的体内降解，但不干扰泛素非依赖的底物。我们的发现提出了一种可能性，即hPLIC蛋白，以及可能相关的泛素样家族成员，可能在功能上将泛素化机制与蛋白酶体联系起来，影响体内蛋白质的降解。
Although there is a binding site on the proteasome for the polyubiquitin chains attached to degradation substrates by the ubiquitination machinery, it is currently unclear whether in vivo the activities of the ubiquitination machinery and the proteasome are coupled. Here we shaw that two human homologs of the yeast ubiquitin-like Dsk2 protein, hPLIC-1 and hPLIC-2, physically associate with both proteasomes and ubiquitin ligases in large complexes. Overexpression of hPLIC proteins interferes with the in vivo degradation of two unrelated ubiquitin-dependent proteasome substrates, p53 and I kappa B alpha, but not a ubiquitin-independent substrate. Our findings raise the possibility that the hPLIC proteins, and possibly related ubiquitin-like family members, may functionally link the ubiquitination machinery to the proteasome to affect in vivo protein degradation.