Is mitochondrial DNA repair mediated by AP endonuclease involved in the pathophysiology of cancer?

线粒体AP核酸内切酶（mtAPE）是一种重要的线粒体DNA修复酶。本研究的目的是阐明mtAPE的身份和功能。在这项研究中，我们研究了AP核酸内切酶1的亚细胞定位，这是一个mtAPE的候选人，并观察到没有APE 1分布在纯线粒体组分。酶活性测定结果表明，纯化的线粒体组分中存在一定的AP内切酶活性和大量的AP裂解酶活性。此外，我们还发现，该AP裂解酶的分子量为30和40 kD之间。

Mitochondrial AP endonuclease (mtAPE), which is unidentified at present, is assumed to be important for mitochondrial DNA repair. This study was aimed to elucidate the identity and function of mtAPE. In this study, we examined the subcellular localization of AP endonuclease 1, which is one of mtAPE candidates, and observed no APE1 distribution in pure mitochondrial fraction. The enzymatic activity tests revealed that there was some AP endonuclease activity and substantial AP lyase activity in pure mitochondrial fraction. Furthermore, we also found that the molecular weight of this AP lyase was between 30 and 40 kD.