Nguyen M M, Livingston D M
Department of Biochemistry, University of Minnesota, Minneopolis 55455, USA.
Yeast. 1997 Sep 15;13(11):1059-64. doi: 10.1002/(SICI)1097-0061(19970915)13:11<1059::AID-YEA165>3.0.CO;2-K.
We have cloned a suppressor of a temperature-sensitive rad52 allele and found it to be a mutation in PUP1, a gene encoding a protease subunit of the 20s proteasome. This identity prompted us to examine the interrelationship among PUP1, RAD52, SRS2 and RAD6 because srs2 mutations not only suppress some rad52 mutations but also suppress deletions of rad6, a gene encoding a protein in the ubiquination-dependent proteolysis pathway. We have found that while srs2 suppresses the UV sensitivity of rad6 in the presence of RAD52, srs2 cannot suppress rad6 when the temperature-sensitive allele of rad52 is present. This inability of srs2 to suppress rad6 is irrespective of the incubation temperature or whether pup1 is suppressing the temperature-sensitive rad52 mutation.
我们克隆了一个温度敏感型rad52等位基因的抑制子，发现它是PUP1基因中的一个突变，PUP1基因编码20S蛋白酶体的一个蛋白酶亚基。这一发现促使我们研究PUP1、RAD52、SRS2和RAD6之间的相互关系，因为srs2突变不仅能抑制一些rad52突变，还能抑制rad6的缺失，rad6是泛素化依赖性蛋白水解途径中一个编码蛋白质的基因。我们发现，虽然在存在RAD52的情况下srs2能抑制rad6的紫外线敏感性，但当存在rad52的温度敏感型等位基因时，srs2不能抑制rad6。srs2无法抑制rad6与孵育温度无关，也与pup1是否抑制温度敏感型rad52突变无关。
