The transcription factor Mrr1p controls expression of the MDR1 efflux pump and mediates multidrug resistance in Candida albicans.
The transcription factor Mrr1p controls expression of the MDR1 efflux pump and mediates multidrug resistance in Candida albicans.
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DOI：
10.1371/journal.ppat.0030164
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发表时间：
2007-11
期刊：
影响因子：
6.7
通讯作者：
Rogers PD
中科院分区：
文献类型：
--
作者：
Morschhäuser J;Barker KS;Liu TT;BlaB-Warmuth J;Homayouni R;Rogers PD
多药耐药(Mdr1)基因编码主要促进剂超家族的多药外排泵，其结构性过表达是临床白色念珠菌对氟康唑等有毒化合物耐药的常见原因，但mdr1上调的机制尚未解决。通过全基因组基因表达分析，我们已经确定了一个锌簇转录因子，命名为MRR1(多药耐药调节因子)，它与mdr1在耐药的临床白色念珠菌分离株中协同上调。在两个这样的耐药分离株中，MRR1的失活消除了MDR1的表达和多药耐药性。对两对匹配的药敏和耐药白念珠菌的MRR1等位基因序列分析表明，耐药株的MRR1等位基因纯合，其中一株发生了P683S交换，另一株发生了G997V置换。将这些突变的等位基因导入对药物敏感的白色念珠菌菌株，导致结构性MDR1过度表达和多药耐药。通过比较耐药白念珠菌及其衍生的mrr1Δ突变株和携带野生型和突变型mrr1等位基因的白念珠菌的转录谱，我们确定了mr1p控制的靶基因。许多mr1p靶基因编码氧化还原酶，其在氟康唑耐药株中的上调可能有助于防止在氟康唑存在下产生有毒分子而导致的细胞损伤，从而导致耐药性。MRR1是mdr1外排泵的中心调节因子，对耐氟康唑的临床白色念珠菌分离株中发生的突变以及导致该转录因子的构成活性的阐明，为深入了解这种重要的人类真菌病原体的多药耐药的分子基础提供了详细的见解。白念珠菌mdr1(多药耐药)基因编码主要促进剂超家族的多药外排泵，在许多氟康唑耐药株中结构性过表达。虽然mdr1的过度表达是这种广泛使用的抗真菌药物和其他代谢抑制剂产生耐药性的主要原因，但到目前为止，耐药株mdr1上调的分子基础仍然不清楚。通过比较mdr1过表达的临床白色念珠菌分离株和来自同一患者的匹配的药物敏感分离株的转录谱，我们发现了一个转录因子，称为多药耐药调节因子1(MRR1)，它在所有耐药分离株中上调，并被证明是mdr1表达的中心调节因子。耐药菌株包含MRR1的点突变，这使得转录因子具有结构性活性。将这些突变的等位基因导入敏感品系会导致MDR1的过度表达和多药耐药。临床分离株中mdr1基因的失活使mdr1基因表达丧失，对氟康唑耐药性的影响甚至比mdr1外排泵基因缺失更强，这表明基因组全基因表达分析鉴定的其他mr1p靶基因与氟康唑耐药有关。这些发现为人类最重要的真菌病原体之一的多重耐药的分子基础提供了详细的见解。
Constitutive overexpression of the MDR1 (multidrug resistance) gene, which encodes a multidrug efflux pump of the major facilitator superfamily, is a frequent cause of resistance to fluconazole and other toxic compounds in clinical Candida albicans strains, but the mechanism of MDR1 upregulation has not been resolved. By genome-wide gene expression analysis we have identified a zinc cluster transcription factor, designated as MRR1 (multidrug resistance regulator), that was coordinately upregulated with MDR1 in drug-resistant, clinical C. albicans isolates. Inactivation of MRR1 in two such drug-resistant isolates abolished both MDR1 expression and multidrug resistance. Sequence analysis of the MRR1 alleles of two matched drug-sensitive and drug-resistant C. albicans isolate pairs showed that the resistant isolates had become homozygous for MRR1 alleles that contained single nucleotide substitutions, resulting in a P683S exchange in one isolate and a G997V substitution in the other isolate. Introduction of these mutated alleles into a drug-susceptible C. albicans strain resulted in constitutive MDR1 overexpression and multidrug resistance. By comparing the transcriptional profiles of drug-resistant C. albicans isolates and mrr1Δ mutants derived from them and of C. albicans strains carrying wild-type and mutated MRR1 alleles, we defined the target genes that are controlled by Mrr1p. Many of the Mrr1p target genes encode oxidoreductases, whose upregulation in fluconazole-resistant isolates may help to prevent cell damage resulting from the generation of toxic molecules in the presence of fluconazole and thereby contribute to drug resistance. The identification of MRR1 as the central regulator of the MDR1 efflux pump and the elucidation of the mutations that have occurred in fluconazole-resistant, clinical C. albicans isolates and result in constitutive activity of this trancription factor provide detailed insights into the molecular basis of multidrug resistance in this important human fungal pathogen. The Candida albicans MDR1 (multidrug resistance) gene encodes a multidrug efflux pump of the major facilitator superfamily that is constitutively overexpressed in many fluconazole-resistant strains. Although MDR1 overexpression is a major cause of resistance to this widely used antifungal agent and other metabolic inhibitors, so far the molecular basis of MDR1 upregulation in resistant strains has remained elusive. By comparing the transcription profiles of MDR1 overexpressing, clinical C. albicans isolates and matched, drug-susceptible isolates from the same patients, we identified a transcription factor, termed multidrug resistance regulator 1 (MRR1), which was upregulated in all resistant isolates and turned out to be a central regulator of MDR1 expression. Resistant isolates contained point mutations in MRR1, which rendered the transcription factor constitutively active. Introduction of these mutated alleles into a susceptible strain caused MDR1 overexpression und multidrug resistance. Inactivation of MRR1 in clinical isolates abolished MDR1 expression and affected fluconazole resistance even more strongly than deletion of the MDR1 efflux pump itself, indicating that additional Mrr1p target genes, which were identified by genome-wide gene expression analysis, contribute to fluconazole resistance. These findings provide detailed insights into the molecular basis of multidrug resistance in one of the most important human fungal pathogens.
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影响因子：
4.9
作者：
Perea, S;López-Ribot, JL;Patterson, TF
通讯作者：
Patterson, TF
影响因子：
4.9
作者：
Hiller, D;Sanglard, D;Morschhäuser, J
通讯作者：
Morschhäuser, J
影响因子：
3.1
作者：
Kusch, H;Biswas, K;Morschhäuser, J
通讯作者：
Morschhäuser, J
影响因子：
3.4
作者：
Kusch, Harald;Engelmann, Susanne;Hecker, Michael
通讯作者：
Hecker, Michael
DOI：
10.1016/s0925-4439(02)00087-x
发表时间：
2002-07-18
影响因子：
6.2
作者：
Morschhäuser, J
通讯作者：
Morschhäuser, J