Interaction of the yeast pleiotropic drug resistance genes PDR1 and PDR5

Meyers, Shirley; Schauer, Wren E.; Balzi, Elisabetta; Wagner, Marisa; Goffeau, André; Golin, John

doi:10.1007/bf00351651

Cited by 150 publications

(123 citation statements)

References 13 publications

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“…However, as with the stable overexpression of the ABC transporters CDR1 and CDR2, the genetic basis for the constitutive activation of the MDR1 gene in such strains has not been elucidated. In Saccharomyces cerevisiae several regulatory proteins (Pdr1p, Pdr3p, and Yap1p) controlling expression of multiple drug resistance genes of the ABC transporter and major-facilitator superfamilies are known (1,3,5,11,12,15,16,20,28,30), and mutations in these regulators that result in upregulation of their respective target genes have been identified (4,19). Recently, functional homologues of these regulators have also been found in C. albicans (1,27); however, conflicting data about the roles of these transcriptional regulators have been obtained.…”

Section: Discussionmentioning

confidence: 99%

Activation of the Multiple Drug Resistance Gene MDR1 in Fluconazole-Resistant, Clinical Candida albicans Strains Is Caused by Mutations in a trans -Regulatory Factor

et al. 2000

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Resistance of Candida albicans against the widely used antifungal agent fluconazole is often due to active drug efflux from the cells. In many fluconazole-resistant C. albicans isolates the reduced intracellular drug accumulation correlates with constitutive strong expression of the MDR1 gene, encoding a membrane transport protein of the major facilitator superfamily that is not detectably expressed in vitro in fluconazole-susceptible isolates. To elucidate the molecular changes responsible for MDR1 activation, two pairs of matched fluconazole-susceptible and resistant isolates in which drug resistance coincided with stable MDR1 activation were analyzed. Sequence analysis of the MDR1 regulatory region did not reveal any promoter mutations in the resistant isolates that might account for the altered expression of the gene. To test for a possible involvement of trans-regulatory factors, a GFP reporter gene was placed under the control of the MDR1 promoter from the fluconazole-susceptible C. albicans strain CAI4, which does not express the MDR1 gene in vitro. This MDR1P-GFP fusion was integrated into the genome of the clinical C. albicans isolates with the help of the dominant selection marker MPA R developed for the transformation of C. albicans wild-type strains. Integration was targeted to an ectopic locus such that no recombination between the heterologous and resident MDR1 promoters occurred. The transformants of the two resistant isolates exhibited a fluorescent phenotype, whereas transformants of the corresponding susceptible isolates did not express the GFP gene. These results demonstrate that the MDR1 promoter was activated by a trans-regulatory factor that was mutated in fluconazoleresistant isolates, resulting in deregulated, constitutive MDR1 expression.Candida albicans is an important opportunistic fungal pathogen of humans and is the major cause of oropharyngeal candidiasis (OPC) in patients with AIDS (21). The azole antifungal agent fluconazole is a widely used compound to treat OPC. In recent years, however, the incidence of treatment failures has been rising. Especially in patients with AIDS who have recurrent OPC and who are receiving prolonged fluconazole therapy, treatment failures are due to the emergence of fluconazole-resistant strains (10, 22). Resistant C. albicans isolates frequently exhibit reduced intracellular drug accumulation that correlates with enhanced expression of certain multiple drug resistance genes, the ATP-binding cassette (ABC) transporters CDR1 and CDR2, and the major facilitator MDR1 (8,14,24,25,29). Fluconazole resistance is usually a stable phenotype that is maintained in the absence of selection pressure by the drug. This implies that genetic alterations have occurred in the resistant isolates that result in a constitutive overexpression of the drug efflux pumps. The MDR1 gene is not detectably expressed in vitro in fluconazole-susceptible C. albicans isolates but is strongly activated in many strains after the development of fluconazole resistance. The molecular chang...

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Section: Discussionmentioning

confidence: 99%

Activation of the Multiple Drug Resistance Gene MDR1 in Fluconazole-Resistant, Clinical Candida albicans Strains Is Caused by Mutations in a trans -Regulatory Factor

et al. 2000

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“…[17][18][19][20][21][22][23][24][25][26][27][28] C. albicans Fcr1p displays significant sequence homology with S. cerevisiae Pdr1p and Pdr3p, and it could confer azole resistance in S. cerevisiae pdr1 pdr3 mutant by regulating PDR5. 16) We hypothesized that Fcr1p maybe involved in the development of C. albicans azole resistance as well as Pdr1p and Pdr3p in S. cerevisiae.…”

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confidence: 99%

Fcr1p Inhibits Development of Fluconazole Resistance in Candida albicans by Abolishing CDR1 Induction

Shen

Wang

et al. 2007

Biological & Pharmaceutical Bulletin

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Candida albicans (C. albicans), the major opportunistic fungal pathogen in humans, causes diseases varying from superficial mucosal complaints to life-threatening systemic disorders. [1][2][3] Coincident with the increased use of antifungal drugs, the incidences of drug resistance have also increased. [4][5][6] In recent years, the development of multidrug resistance in clinical isolates has challenged effective treatment of the infections. Specifically, the extensive and repetitive use of antifungal azole derivatives such as fluconazole (FLC) has allowed C. albicans to utilize many mechanisms of resistance in order to ensure its survival. 7,8) This situation highlights the need for elucidating the mechanism of drug resistance in C. albicans to develop new antifungal agents.Overexpression of efflux pumps, either ATP-binding cassette (ABC) or major facilitator superfamily (MFS) transporters, has been shown to be one of the major mechanisms of drug resistance in clinical isolates because if causes active extrusion of the drug out of the cell. 9-11) The Candida drug resistance 1 (CDR1) gene, which encodes an ABC efflux pump, is identified by complementation of the pleiotropic drug resistance 5 (pdr5) mutant, which is hypersensitive to cycloheximide, chloramphenicol, and azole drugs, in Saccharomyces cerevisiae (S. cerevisiae). 12) C. albicans cdr1 mutant resulted in increasing susceptibilities to azole drugs, 13) which is consistent with the observation that overexpression of CDR1 contributes to the drug resistance of clinical isolates of C. albicans. 6,14) Furthermore, the existence of trans-regulatory factors of CDR1 has also been suggested. 15) However, the molecular mechanism and the gene network regulating the expression of CDR1 and drug resistance are poorly understood.C. albicans Fcr1p (for fluconazole resistance 1 protein), a member of the family of zinc cluster proteins, is characterized by a highly conserved Zn(II) 2 Cys 6 zinc finger motif within the N-terminal DNA binding domain (DBD). 16) Well known Pdr1p and Pdr3p (pleiotropic drug resistance protein) zinc cluster proteins regulate the expression of several multidrug ABC transporter genes including PDR5, SNQ2, and YOR1, causing azole resistance in S. cerevisiae. 17-28) C. albicans Fcr1p displays significant sequence homology with S. cerevisiae Pdr1p and Pdr3p, and it could confer azole resistance in S. cerevisiae pdr1 pdr3 mutant by regulating PDR5. 16) We hypothesized that Fcr1p maybe involved in the development of C. albicans azole resistance as well as Pdr1p and Pdr3p in S. cerevisiae.In the present study we investigated the role of Fcr1p in the development of C. albicans azole resistance and possible mechanisms in vitro and in vivo. The results showed that Fcr1p inhibited development of fluconazole resistance in C. albicans through abolishing the induction of CDR1 expression by FLC, and in contrast FLC resistance development was accelerated resulting from the deletion of FCR1. (Table 1). MATERIALS AND METHODS Strains and MediaThe strains were cul...

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“…The functions of Pdr1 and Pdr3 overlap; however, Pdr3, but not Pdr1, is subject to auto-regulation (Delahodde et al 1995). Several substitution mutations within Pdr1 result in a hyperactive activator (e.g., F815S in the Pdr1-3 hyperactivator protein encoded by the pdr1-3 allele (Meyers et al 1992;Carvajal et al 1997) that increases the transcription of many genes encoding ABC transporters (including PDR5), as well as permeases and enzymes involved in lipid and cell-wall synthesis (DeRisi et al 2000). Similarly to Pdr1, several hyperactive Pdr3 activators, including that encoded by the pdr3-2 allele, were identified (Nourani et al 1997).…”

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confidence: 99%

ELM1 Is Required for Multidrug Resistance in Saccharomyces cerevisiae

Souid

Gao²,

Wang³

et al. 2006

Genetics

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In Saccharomyces cerevisiae, transcription of several drug transporter genes, including the major transporter gene PDR5, has been shown to peak during mitosis. The significance of this observation, however, remains unclear. PDR1 encodes the primary transcription activator of multiple drug transporter genes in S. cerevisiae, including PDR5. Here, we show that in synchronized PDR1 and pdr1-3 (multidrug resistant) strains, cellular efflux of a known substrate of ATP-binding-cassette transporters, doxorubicin (a fluorescent anticancer drug), is highest during mitosis when PDR5 transcription peaks. A genetic screen performed to identify regulators of multidrug resistance revealed that a truncation mutation in ELM1 (elm1-300) suppressed the multidrug resistance of pdr1-3. ELM1 encodes a serine/threonine protein kinase required for proper regulation of multiple cellular kinases, including those involved in mitosis, cytokinesis, and cellular morphogenesis. elm1-300 as well as elm1D mutations in a pdr1-3 strain also caused elongated bud morphology (indicating a G 2 /M delay) and reduction of PDR5 transcription under induced and noninduced conditions. Interestingly, mutations in several genes functionally related to ELM1, including cla4D, gin4D, and cdc28-C127Y, also caused drastic reductions in drug resistance and PDR5 transcription. Collectively, these data show that ELM1, and genes encoding related serine/threonine protein kinases, are required for regulation of multidrug resistance involving, at least in part, control of PDR5 transcription.

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Interaction of the yeast pleiotropic drug resistance genes PDR1 and PDR5

Cited by 150 publications

References 13 publications

Activation of the Multiple Drug Resistance Gene MDR1 in Fluconazole-Resistant, Clinical Candida albicans Strains Is Caused by Mutations in a trans -Regulatory Factor

Activation of the Multiple Drug Resistance Gene MDR1 in Fluconazole-Resistant, Clinical Candida albicans Strains Is Caused by Mutations in a trans -Regulatory Factor

Fcr1p Inhibits Development of Fluconazole Resistance in Candida albicans by Abolishing CDR1 Induction

ELM1 Is Required for Multidrug Resistance in Saccharomyces cerevisiae

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