PMID:2257633 Identification of an amino acid substitution in the benA, beta-tubulin gene of Aspergillus nidulans that confers thiabendazole resistance and benomyl supersensitivity

[MPiovesana]

Curated by @MPiovesana https://canto.phi-base.org/curs/1c6883fef59a7aaf

[MPiovesana]

In this paper, authors describe a new strategy to clone benA (β-tubulin) mutant alleles of Aspergillus nidulans using a marker-rescue technique. The mutant alleles benA16 and benA19 are known to confer supersensitivity to benomyl. Upon cloning the benA(A165V) alleles from mutant strains, the authors introduce them into strain G191 (benA+), with the resulting transformants displaying an intermediate sensitivity phenotype between sensitive and resistant strains.

[MPiovesana]

Uniprot ID: a gene (beta tubulin) and species name (Aspergillus nidulans) search returned entry P10653 for the benA gene of A. nidulans.

Strain: strain G191 was manually added to the curation session.

[MPiovesana]

Genotype creation: I curated the genotype of the transformants obtained by introducing the benA16/19 mutant alleles in strain G191. As the plasmids used for transformation lead to the integration of the benA mutant allele in the endogenous benA locus, the resulting transformants seemingly carry three copies of the benA gene: the two endogenous benA wild type copies (Endogenous benA present added in background), and one mutant copy of the benA mutant allele (authors mention in the text that most transformants only carry one integrated copy of the mutant allele in the benA locus). I initially thought this could be recorded as a diploid, heterozygous locus, but I do not think this would work here as the locus where transgene integration occurs carries both a wt and a mutant copy of the gene, while the other locus remains unchanged. Thus, I created a transformant allele type as below:

benA transformant(BEN17-benA(A165V)) [Not assayed]: indicating the transformation of the mutant benA allele from strain BEN17 (one of the strains described in the paper picked as representative, as authors do not specify which strain was used as template to clone gene) in recipient strain. Endogenous benA present was added in background.

AC: BEN17 is supersensitive to benomyl

[MPiovesana]

Genotype annotation: the transformants carrying the wt benA and the BEN17-benA(A165V) alleles exhibit an intermediate sensitivity phenotype to benomyl compared to homozygous strains (Figure 3). As the recipient strain G191 is a benA+ strain, I considered its phenotype as a control. Thus, I assigned the mutant genotype with PHIPO term sensitive to benomyl, and added annotation extension has_severity medium to record the intermediate phenotype observed.

[MPiovesana]

Curation completed pending review.

[CuzickA]

Looks good

Approving session

[CuzickA]

AE alteration_in _archetype

A165V; BenA (β-tubulin); ASPEND

Straight forward to find in Nichola's S file in Table S1

Question Are we happy with target-site name, see https://github.com/PHI-base/curation/issues/144 Yes, this follows our guidance in the FAQs

[CuzickA]

AE alteration_in _archetype checked by Nichola. Session now approved.