Portillo F
Departamento de Bioquímica de la Facultad de Medicina de la Universidad Autónoma de Madrid, Spain.
FEBS Lett. 1997 Feb 3;402(2-3):136-40. doi: 10.1016/s0014-5793(96)01515-3.
Site-directed mutants of yeast ATPase were studied after introduction of mutant alleles into a yeast strain where these alleles were constitutively expressed and the expression of the wild-type chromosomal ATPase gene was turned off. One objection to this constitutive expression system was made apparent recently, as dominant lethal mutations are lost by gene conversion with the wild-type allele during the process. Here, the phenotypes of the mutant alleles, which were studied in a constitutive expression system, are re-evaluated under conditions in which these site-directed mutants are conditionally expressed. We show that 12 of 25 site-directed mutations previously described are actually dominant lethal alleles. In addition, we show that dominant mutant proteins interfere with transport of wild-type ATPase to the plasma membrane.
将酵母ATP酶的突变等位基因导入一个酵母菌株后，对定点突变体进行了研究。在该菌株中，这些等位基因组成型表达，而野生型染色体ATP酶基因的表达被关闭。最近，对这种组成型表达系统的一个反对意见变得明显，因为在这个过程中，显性致死突变会通过与野生型等位基因的基因转换而丢失。在这里，在定点突变体条件性表达的条件下，对在组成型表达系统中研究的突变等位基因的表型进行了重新评估。我们发现，先前描述的25个定点突变中有12个实际上是显性致死等位基因。此外，我们还表明，显性突变蛋白会干扰野生型ATP酶向质膜的转运。
