PMID:22155829 Identification of a Cryptococcus neoformans cytochrome P450 lanosterol 14α-demethylase (Erg11) residue critical for differential susceptibility between fluconazole/voriconazole and itraconazole/posaconazole

[MPiovesana]

Curated by @MPiovesana https://canto.phi-base.org/curs/dbfd816d79641ac0

[MPiovesana]

In this papers authors identify a mutant allele of the ERG11 gene of Cryptococcus neoformans that confers high levels of resistance to azoles. The wild type ERG11 allele of the reference strain H99 was replaced with the mutant allele from clinical isolate MRL862, carrying 5 point mutations. Authors also manipulated the MRL862 allele to remove some of the point mutations, and identified a single one (Y145F) as being responsible for the azole resistance phenotype.

AC: The strain TES9 derived from MRL862 contained the single mutation (Y145F) responsible for the phenotypes. It is a bit hard to know whether the transformant strain name should be MRL862 or TES9. For now I have left it as it is which is MRL862 (ERG11 transformant(MRL862-ERG11(Y145F))[Not assayed]). MRL862 contains 4 point mutations in ERG11 that do not affect the phenotype and one (Y145F), which is recorded within the genotype, that does change the phenotype.

[MPiovesana]

Uniprot ID: the GenBank accession number of ERG11 from recipient strain H99 was provided by the authors (JQ044790) and was used to retrieve ID Q870D1 from Uniprot.

Strain: strain H99 was added to curation session as the recipient for transformation experiments.

[MPiovesana]

Genotype creation: an allele type transformant was created to record the genotype of the H99 strain transformed with the modified ERG11 allele from MRL862 harbouring the Y145F mutation. The deletion of the endogenous ERG11 was recorded in background.

Genotype annotation: genotype was annotated with the following PHIPO terms: resistance to fluconazole resistance to voriconazole sensitive to itraconazole sensitive to posaconazole

[MPiovesana]

NOTE: authors also test the susceptibility of the C. neoformans strains in vivo in infected mice. All strains cause 100% mortality with our without FLC treatment, but mice survived longer when infected parental H99 or H99 transformed with ERG11-Y145F allele. Not sure whether this is relevant for curation, but could be discussed.

AC: Looks like this might be a bit tricky to curate so will probably leave it out for now. The graphs in Fig 3 and 4 are comparing treatment or lack of treatment within the PHI for each pathogen strain/mutation rather than WT ERG11 vs ERG11-Y145F. Comparing Fig 3A (H99) and D (TES9) and also Fig4A (H99) and D (TES9) untreated, there doesn't seem to be a big difference in mouse survival between WT ERG11 (H99) vs ERG11-Y145F (TES9).

[MPiovesana]

Curation completed pending review.

[CuzickA]

Adding AE alteration in archetype Query - which cyp51a or cyp51b paralogue to map single copy erg11/cyp51 to? Could not find Cryptococcus neoformans/Filobasidiella neoformans listed in Nichola's S files. In Mair et al 2016, I have found this information (nothing of note in table 2 for cyp51a) EPPO code FILBNF is for Filobasidiella neoformans https://gd.eppo.int/taxon/FILBNF

Therefore I believe the AE would be Y137F; ERG11 (Cyp51B); SEPTTR

[CuzickA]

Approving session and closing ticket.

[CuzickA]

AE alteration_in _archetype

Y137F; ERG11 (Cyp51B); SEPTTR

Questions for Nichola 1) Which cyp51a or cyp51b paralogue, same question as #172 AC: Cyp51B 2) Could not find Cryptococcus neoformans/Filobasidiella neoformans listed in Nichola's S files. Is it okay to use the above info. from the Mair et al 2016 paper? Please check 'Y137F; ERG11 (Cyp51B); SEPTTR' This is correct.

[CuzickA]

AE alteration_in _archetype checked by Nichola. Session now approved.