Alimardani Parissa, Régnacq Matthieu, Moreau-Vauzelle Carole, Ferreira Thierry, Rossignol Tristan, Blondin Bruno, Bergès Thierry
Laboratoire de Génétique de la Levure, CNRS-UMR 6161, Université de Poitiers, 40 avenue du Recteur Pineau, 86022 Poitiers Cedex, France.
Biochem J. 2004 Jul 1;381(Pt 1):195-202. doi: 10.1042/BJ20040297.
Efficient sterol influx in the yeast Saccharomyces cerevisiae is restricted to anaerobiosis or to haem deficiency resulting from mutations. Constitutive expression of SUT1, an hypoxic gene encoding a transcriptional regulator, induces sterol uptake in aerobiosis. A genome-wide approach using DNA microarray was used to identify the mediators of SUT1 effects on aerobic sterol uptake. A total of 121 ORFs (open reading frames) were significantly and differentially expressed after SUT1 overexpression, 61 down-regulated and 60 up-regulated. Among these genes, the role of the putative ABC transporter (ATP-binding-cassette transporter) Aus1, and of the cell-wall mannoprotein Dan1, was characterized better. These two genes play an essential role in aerobic sterol uptake, since their deletion compromised the SUT1 effects, but individual overexpression of either of these genes in a wild-type background was not sufficient for this process. However, constitutive co-expression of AUS1 and DAN1 in a wild-type background resulted in sterol influx in aerobiosis. These results suggest that the corresponding proteins may act synergistically in vivo to promote sterol uptake.
酿酒酵母中高效的甾醇流入仅限于无氧状态或由突变导致的血红素缺乏。SUT1是一个编码转录调节因子的缺氧基因，其组成型表达可在需氧条件下诱导甾醇摄取。利用DNA微阵列的全基因组方法来鉴定SUT1对需氧甾醇摄取作用的介导因子。SUT1过表达后，共有121个开放阅读框（ORF）出现显著差异表达，其中61个下调，60个上调。在这些基因中，对假定的ABC转运蛋白（ATP结合盒转运蛋白）Aus1和细胞壁甘露糖蛋白Dan1的作用研究得更为深入。这两个基因在需氧甾醇摄取中起重要作用，因为它们的缺失会损害SUT1的作用，但在野生型背景下单独过表达这两个基因中的任何一个对于此过程都是不够的。然而，在野生型背景下组成型共表达AUS1和DAN1会导致需氧条件下的甾醇流入。这些结果表明相应的蛋白质可能在体内协同作用以促进甾醇摄取。
