Negative regulation of <i>Candida glabrata</i> Pdr1 by the deubiquitinase subunit Bre5 occurs in a ubiquitin independent manner

Paul, Sanjoy; Moye‐Rowley, W. Scott

doi:10.1111/mmi.14109

Cited by 13 publications

(14 citation statements)

References 62 publications

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“…When driven from the MET3 promoter, GOF forms accumulated to a lower level than the wild-type protein yet target gene transcription was higher. Our previous data have indicated that the Bre5 protein appears to be a negative regulator of Pdr1 levels in C. glabrata and strains lacking Bre5 accumulated higher levels of Pdr1 than wild-type cells [15]. Additionally, GOF forms of Pdr1 were degraded at a faster rate than the wild-type protein [10].…”

Section: Discussionmentioning

confidence: 95%

“…Our previous data have indicated that the Bre5 protein appears to be a negative regulator of Pdr1 levels in C . glabrata and strains lacking Bre5 accumulated higher levels of Pdr1 than wild-type cells [ 15 ]. Additionally, GOF forms of Pdr1 were degraded at a faster rate than the wild-type protein [ 10 ].…”

Section: Discussionmentioning

confidence: 99%

“…The C-terminal activation domain of Pdr1 (residues 968-1107) may be released from intramolecular repression by changes such as D1082G, LWG1097AAA, multiple mutations in the CRD or deletion of the entire CRD as in the internal deletion Δ255-968 Pdr1. It is also possible that interactions with the trans-acting negative regulators Bre5 and Jjj1 might also be involved in the effects seen for the impact of C-terminal mutagenesis [14,15]. We speculate that the D1082 and LWG1097 regions also have positive interactions with co-activators other than Med15A as the combination of mutational alterations in these two regions, coupled with deletion of MED15A, caused the most profound defect in Pdr1-mediated fluconazole resistance and Cdr1 expression (Fig 8).…”

Section: Plos Geneticsmentioning

confidence: 96%

“…Experiments aimed at identifying interacting proteins with the Pdr1 TAD demonstrated the Mediator subunit Med15A binds to the C-terminal 34 residues and provided evidence that this binding is required to fully drive induced gene expression [13]. Genetic and biochemical experiments have identified two trans-acting negative regulators of Pdr1 activity-Jjj1 and Bre5, although their target region within Pdr1 remains unknown [14,15]. While a broad spectrum of GOF forms of Pdr1 have been identified, how these lesions trigger the high-level transactivation of Pdr1 target genes is not understood.…”

Section: Introductionmentioning

confidence: 99%

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Functional information from clinically-derived drug resistant forms of the Candida glabrata Pdr1 transcription factor

Simonicova

Moye‐Rowley

2020

PLoS Genet

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Azole drugs are the most frequently used antifungal agents. The pathogenic yeast Candida glabrata acquires resistance to azole drugs via single amino acid substitution mutations eliciting a gain-of-function (GOF) hyperactive phenotype in the Pdr1 transcription factor. These GOF mutants constitutively drive high transcription of target genes such as the ATP-binding cassette transporter-encoding CDR1 locus. Previous characterization of Pdr1 has demonstrated that this factor is negatively controlled by the action of a central regulatory domain (CRD) of~700 amino acids, in which GOF mutations are often found. Our earlier experiments demonstrated that a Pdr1 derivative in which the CRD was deleted gave rise to a transcriptional regulator that could not be maintained as the sole copy of PDR1 in the cell owing to its toxically high activity. Using a set of GOF PDR1 alleles from azole-resistant clinical isolates, we have analyzed the mechanisms acting to repress Pdr1 transcriptional activity. Our data support the view that Pdr1-dependent transactivation is mediated by a complex network of transcriptional coactivators interacting with the extreme C-terminal part of Pdr1. These coactivators include but are not limited to the Mediator component Med15A. Activity of this C-terminal domain is controlled by the CRD and requires multiple regions across the C-terminus for normal function. We also provide genetic evidence for an element within the transactivation domain that mediates the interaction of Pdr1 with coactivators on one hand while restricting Pdr1 activity on the other hand. These data indicate that GOF mutations in PDR1 block nonidentical negative inputs that would otherwise restrain Pdr1 transcriptional activation. The strong C-terminal transactivation domain of Pdr1 uses multiple different protein regions to recruit coactivators.

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Section: Discussionmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 99%

Section: Plos Geneticsmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Functional information from clinically-derived drug resistant forms of the Candida glabrata Pdr1 transcription factor

Simonicova

Moye‐Rowley

2020

PLoS Genet

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“…Western blotting of C. glabrata whole-cell protein extracts was performed as previously described (42), and extracts were prepared using NaOH/β-mercaptoethanol-based lysis. All Western blot experiments were performed in triplicate, and the results were quantitated using Odyssey software and are presented as averages of these determinations with standard errors.…”

Section: Methodsmentioning

confidence: 99%

Evidence that Ergosterol Biosynthesis Modulates Activity of the Pdr1 Transcription Factor in Candida glabrata

Thomas

Moye‐Rowley

2019

mBio

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A crucial limitation in antifungal chemotherapy is the limited number of antifungal drugs currently available. Azole drugs represent the most commonly used chemotherapeutic, and loss of efficacy of these drugs is a major risk factor in successful treatment of a variety of fungal diseases. Candida glabrata is a pathogenic yeast that is increasingly found associated with bloodstream infections, a finding likely contributed to by its proclivity to develop azole drug resistance. C. glabrata often acquires azole resistance via gain-of-function (GOF) mutations in the transcription factor Pdr1. These GOF forms of Pdr1 drive elevated expression of target genes, including the ATP-binding cassette transporter-encoding CDR1 locus. GOF alleles of PDR1 have been extensively studied, but little is known of how Pdr1 is normally regulated. Here we test the idea that reduction of ergosterol biosynthesis (as occurs in the presence of azole drugs) might trigger activation of Pdr1 function. Using two different means of genetically inhibiting ergosterol biosynthesis, we demonstrated that Pdr1 activity and target gene expression are elevated in the absence of azole drug. Blocks at different points in the ergosterol pathway lead to Pdr1 activation as well as to induction of other genes in this pathway. Delivery of the signal from the ergosterol pathway to Pdr1 involves the transcription factor Upc2A, an ERG gene regulator. We show that Upc2A binds directly to the PDR1 and CDR1 promoters. Our studies argue for a physiological link between ergosterol biosynthesis and Pdr1-dependent gene regulation that is not restricted to efflux of azole drugs. IMPORTANCE A likely contributor to the increased incidence of non-albicans candidemias involving Candida glabrata is the ease with which this yeast acquires azole resistance, in large part due to induction of the ATP-binding cassette transporter-encoding gene CDR1. Azole drugs lead to induction of Pdr1 transactivation, with a central model being that this factor binds these drugs directly. Here we provide evidence that Pdr1 is activated without azole drugs by the use of genetic means to inhibit expression of azole drug target-encoding gene ERG11. These acute reductions in Erg11 levels lead to elevated Pdr1 activity even though no drug is present. A key transcriptional regulator of the ERG pathway, Upc2A, is shown to directly bind to the PDR1 and CDR1 promoters. We interpret these data as support for the view that Pdr1 function is responsive to ergosterol biosynthesis and suggest that this connection reveals the normal physiological circuitry in which Pdr1 participates.

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Candida glabrata Hst1-Rfm1-Sum1 complex evolved to control virulence-related genes

Vázquez-Franco

Gutiérrez-Escobedo

Juárez-Reyes

et al. 2022

Fungal Genetics and Biology

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Negative regulation of Candida glabrata Pdr1 by the deubiquitinase subunit Bre5 occurs in a ubiquitin independent manner

Cited by 13 publications

References 62 publications

Functional information from clinically-derived drug resistant forms of the Candida glabrata Pdr1 transcription factor

Functional information from clinically-derived drug resistant forms of the Candida glabrata Pdr1 transcription factor

Evidence that Ergosterol Biosynthesis Modulates Activity of the Pdr1 Transcription Factor in Candida glabrata

Candida glabrata Hst1-Rfm1-Sum1 complex evolved to control virulence-related genes

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