Ramotar D, Vadnais J, Masson J Y, Tremblay S
Maisonneuve-Rosemont Hospital, Research Center, Montreal, Que., Canada.
Biochim Biophys Acta. 1998 Mar 4;1396(1):15-20. doi: 10.1016/s0167-4781(97)00160-7.
The Apn1 protein of the budding yeast Saccharomyces cerevisiae is a DNA repair enzyme that hydrolyzes apurinic/apyrimidinic (AP) sites and removes 3'-blocking groups present at single strand breaks of damaged DNA. Yeast cells lacking Apn1 are hypersensitive to DNA damaging agents that produce AP sites and DNA strand breaks with blocked 3'-termini. In this study, we showed that the fission yeast Schizosaccharomyces pombe bears a homologue, Spapn1, that is 45% identical to S. cerevisiae Apn1. However, the Spapn1 gene is apparently not expressed. Active expression of S. cerevisiae Apn1 in S. pombe conferred no additional resistance to DNA damaging agents. These data suggest that the pathway by which S. pombe repairs AP sites is independent of a functional Apn1-like AP endonuclease.
芽殖酵母酿酒酵母的Apn1蛋白是一种DNA修复酶，可水解脱嘌呤/脱嘧啶（AP）位点，并去除受损DNA单链断裂处存在的3'-阻断基团。缺乏Apn1的酵母细胞对产生AP位点和具有3'-末端阻断的DNA链断裂的DNA损伤剂高度敏感。在本研究中，我们表明裂殖酵母粟酒裂殖酵母带有一个同源物Spapn1，它与酿酒酵母Apn1有45%的同一性。然而，Spapn1基因显然不表达。酿酒酵母Apn1在粟酒裂殖酵母中的活性表达并未赋予对DNA损伤剂的额外抗性。这些数据表明，粟酒裂殖酵母修复AP位点的途径独立于功能性Apn1样AP内切核酸酶。
