Selenate sensitivity of a laeA mutant is restored by overexpression of the bZIP protein MetR in Aspergillus fumigatus

Fungal Genetics and Biology : FG & B
Sachin JainNancy P Keller

Abstract

LaeA is a conserved global regulator of secondary metabolism and development in filamentous fungi. Examination of Aspergillus fumigatus transcriptome data of laeA deletion mutants have been fruitful in identifying genes and molecules contributing to the laeA mutant phenotype. One of the genes significantly down regulated in A. fumigatus ΔlaeA is metR, encoding a bZIP DNA binding protein required for sulfur and methionine metabolism in fungi. LaeA and MetR deletion mutants exhibit several similarities including down regulation of sulfur assimilation and methionine metabolism genes and ability to grow on the toxic sulfur analog, sodium selenate. However, unlike ΔmetR, ΔlaeA strains are able to grow on sulfur, sulfite, and cysteine. To examine if any parameter of the ΔlaeA phenotype is due to decreased metR expression, an over-expression allele (OE::metR) was placed in a ΔlaeA background. The OE::metR allele could not significantly restore expression of MetR regulated genes in ΔlaeA but did restore sensitivity to sodium selenate. In A. nidulans a second bZIP protein, MetZ, also regulates sulfur and methionine metabolism genes. However, addition of an OE::metZ construct to the A. fumigatus ΔlaeA OE::metR strain still was unable to ...Continue Reading

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Aspergillosis (ASM)

Aspergillosis is the name given to a wide variety of diseases caused by infection by fungi of the genus Aspergillus. Aspergillosis occurs in chronic or acute forms which are clinically very distinct. Most cases of acute aspergillosis occur in patients with severely compromised immune systems. Chronic colonization or infection can cause complications in people with underlying respiratory illnesses. Discover the latest research on aspergillosis here.

Aspergillosis

Aspergillosis is the name given to a wide variety of diseases caused by infection by fungi of the genus Aspergillus. Aspergillosis occurs in chronic or acute forms which are clinically very distinct. Most cases of acute aspergillosis occur in patients with severely compromised immune systems. Chronic colonization or infection can cause complications in people with underlying respiratory illnesses. Discover the latest research on aspergillosis here.