van den Hazel H B, Pichler H, do Valle Matta M A, Leitner E, Goffeau A, Daum G
Unité de Biochimie Physiologique, Université Catholique de Louvain, Belgium.
J Biol Chem. 1999 Jan 22;274(4):1934-41. doi: 10.1074/jbc.274.4.1934.
The Saccharomyces cerevisiae open reading frame YNL231C was recently found to be controlled by the multiple drug resistance regulator Pdr1p. Here we characterize YNL231C (PDR16) and its homologue YNL264C (PDR17). Deletion of PDR16 resulted in hypersensitivity of yeast to azole inhibitors of ergosterol biosynthesis. While no increase in drug sensitivity was found upon deletion of PDR17 alone, a Deltapdr16,Deltapdr17 double mutant was hypersensitive to a broad range of drugs. Both mutations caused significant changes of the lipid composition of plasma membrane and total cell extracts. Deletion of PDR16 had pronounced effects on the sterol composition, whereas PDR17 deletion mainly affected the phospholipid composition. Thus, Pdr16p and Pdr17p may regulate yeast lipid synthesis like their distant homologue, Sec14p. The azole sensitivity of the PDR16-deleted strain may be the result of imbalanced ergosterol synthesis. Impaired plasma membrane barrier function resulting from a change in the lipid composition appears to cause the increased drug sensitivity of the double mutant strain Deltapdr16,Deltapdr17. The uptake rate of rhodamine-6-G into de-energized cells was shown to be almost 2-fold increased in a Deltapdr16,Deltapdr17 strain as compared with wild-type and Deltapdr5 strains. Collectively, our results indicate that PDR16 and PDR17 control levels of various lipids in various compartments of the cell and thereby provide a mechanism for multidrug resistance unrecognized so far.
酿酒酵母开放阅读框YNL231C最近被发现受多药耐药调节因子Pdr1p的调控。在此，我们对YNL231C（PDR16）及其同源物YNL264C（PDR17）进行了表征。PDR16的缺失导致酵母对麦角固醇生物合成的唑类抑制剂高度敏感。虽然单独缺失PDR17未发现药物敏感性增加，但Pdr16Δ、Pdr17Δ双突变体对多种药物高度敏感。这两种突变均导致质膜和全细胞提取物的脂质组成发生显著变化。PDR16的缺失对固醇组成有显著影响，而PDR17的缺失主要影响磷脂组成。因此，Pdr16p和Pdr17p可能像它们的远亲同源物Sec14p一样调节酵母脂质合成。缺失PDR16菌株的唑敏感性可能是麦角固醇合成失衡的结果。脂质组成变化导致的质膜屏障功能受损似乎导致了双突变体菌株Pdr16Δ、Pdr17Δ药物敏感性增加。与野生型和Pdr5Δ菌株相比，在Pdr16Δ、Pdr17Δ菌株中，罗丹明-6-G进入去能细胞的摄取率显示几乎增加了2倍。总的来说，我们的结果表明，PDR16和PDR17控制细胞各部分中各种脂质的水平，从而提供了一种迄今为止未被认识的多药耐药机制。
