McCusker J H, Haber J E
Department of Biology, Brandeis University, Waltham, Massachusetts 02254.
Mol Cell Biol. 1990 Jun;10(6):2941-9. doi: 10.1128/mcb.10.6.2941-2949.1990.
Four new complementation groups of mutations which confer resistance to several amino acid analogs in Saccharomyces cerevisiae are described. These mutants were isolated on medium containing urea as the nitrogen source, in contrast to previous studies that had used medium containing proline. All four resistance to amino acid analog (raa) complementation groups appear to confer resistance by reducing amino acid analog and amino acid uptake. In some genetic backgrounds, raa leu2 and raa thr4 double mutants are inviable, even on rich medium. The raa4 mutation may affect multiple amino acid transport systems, since raa4 mutants are unable to use proline as a nitrogen source. raa4 is, however, unlinked to a previously described amino acid analog resistance and proline uptake mutant, aap1, or to the general amino acid permease mutant gap1. Both raa4 and gap1 prevent uptake of [3H]leucine in liquid cultures. The raa1, raa2, and raa3 mutants affect only a subset of the amino acid analogs and amino acids affected by raa4. The phenotypes of raa1, -2, and -3 mutants are readily observed on agar plates but are not seen in uptake and incorporation of amino acids measured in liquid media.
本文描述了酿酒酵母中四个新的突变互补群，这些突变赋予了对几种氨基酸类似物的抗性。与之前使用含脯氨酸培养基的研究不同，这些突变体是在以尿素作为氮源的培养基上分离得到的。所有四个氨基酸类似物抗性（raa）互补群似乎都是通过减少氨基酸类似物和氨基酸的摄取来赋予抗性的。在某些遗传背景下，raa leu2和raa thr4双突变体即使在丰富培养基上也无法存活。raa4突变可能影响多个氨基酸转运系统，因为raa4突变体无法将脯氨酸用作氮源。然而，raa4与先前描述的氨基酸类似物抗性和脯氨酸摄取突变体aap1或一般氨基酸通透酶突变体gap1没有连锁关系。raa4和gap1都能阻止液体培养物中[3H]亮氨酸的摄取。raa1、raa2和raa3突变体只影响raa4所影响的一部分氨基酸类似物和氨基酸。raa1、-2和-3突变体的表型在琼脂平板上很容易观察到，但在液体培养基中测量的氨基酸摄取和掺入中则看不到。
