Hayashi N, Seino H, Irie K, Watanabe M, Clark K L, Matsumoto K, Nishimoto T
Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka, Japan.
Mol Gen Genet. 1996 Nov 27;253(1-2):149-56. doi: 10.1007/s004380050307.
The Saccharomyces cerevisiae temperature-sensitive mutants srm1-1, mtr1-2 and prp20-1 carry alleles of a gene encoding a homolog of mammalian RCC1. In order to identify a protein interacting with RCC1, a series of suppressors of the srm1-1 mutation were isolated as cold-sensitive mutants and one of the mutants, designated ded1-21, was found to be defective in the DED1 gene. The double mutant, srm1-1 ded1-21, could grow at 35 degrees C, but not at 37 degrees C. A revertant of srm1-1 ded1-21 that became able to grow at 37 degrees C acquired another mutation in the SRM1 gene, indicating the tight relationship between SRM1 and DED1. In all the rcc1- strains examined, the amount of mutated SRM1 proteins was reduced or not detectable at the nonpermissive temperature. While mutated SRM1 protein was stabilized in all of the rcc1- strains by the ded1-21 mutation, the ded1-21 mutation suppressed both srm1-1 and mtr1-2, but not the prp20-1 mutation, contrary to the previous finding that overproduction of the S. cerevisiae Ran homolog GSP1 suppresses prp20-1, but not srm1-1 or mtr1-2.
酿酒酵母温度敏感突变体srm1-1、mtr1-2和prp20-1携带一个编码哺乳动物RCC1同源物的基因的等位基因。为了鉴定与RCC1相互作用的蛋白质，一系列srm1-1突变的抑制子作为冷敏感突变体被分离出来，其中一个突变体命名为ded1-21，发现其DED1基因存在缺陷。双突变体srm1-1 ded1-21能在35℃生长，但不能在37℃生长。srm1-1 ded1-21的一个回复突变体能够在37℃生长，它在SRM1基因中获得了另一个突变，这表明SRM1和DED1之间存在紧密关系。在所有检测的rcc1-菌株中，在非允许温度下，突变的SRM1蛋白的量减少或无法检测到。虽然ded1-21突变使所有rcc1-菌株中的突变SRM1蛋白稳定，但ded1-21突变抑制了srm1-1和mtr1-2，但不抑制prp20-1突变，这与之前的发现相反，即酿酒酵母Ran同源物GSP1的过量表达抑制prp20-1，但不抑制srm1-1或mtr1-2。
