SUMOylation is involved in the degradation of DNA topoisomerase IIβ induced by antitumor drug treatment

DNA拓扑异构酶II(Topo II)的降解是由Topo II抑制剂诱导的。TOPO IIβ第1259位氨基酸残基在降解前被SUMO-2/3修饰。赖氨酸到精氨酸的取代(K1259R)没有被相扑修饰，在其被抑制后阻止了降解。另一方面，同样的药物不能诱导TOPO IIα的降解，尽管它的活性受到类似的抑制。过表达实验和对SUMO化位点的分析表明，抑制后它们命运的差异取决于SUMO化位点的存在或不存在，而不是表达时机或核定位。

Degradation of DNA topoisomerase II (Topo II) was induced by Topo II inhibitors. The lysine residue at amino acid position 1259 of Topo IIβ was modified by SUMO-2/3 in advance of the degradation. The lysine-to-arginine substitution (K1259R), which was not modified by SUMO, prevented the degradation following its inhibition. On the other hand, the same drugs did not induce the degradation of Topo IIα although its activity was inhibited similarly. Over-expression experiments and analysis of SUMOylation sites suggested that the difference in their fate after inhibition depends on the presence or absence of SUMOylation site, not on the expression timing or nuclear localization.