Fungi - Candida albicans - Research News, Data, Publications & Aproaches - ERG11 Mutations - Telomeres - Nuclear Biology & Nuclear Chemistry Aproaches - Heme-Dependant Nuclear Chemistry - Non-Elaborate Posts - Post 6


Within this oxidative setting, heme functions as a redox-responsive transcriptional cofactor. The nuclear pool of heme alternates between ferric (Fe³⁺) and ferrous (Fe²⁺) states, influencing the binding of heme-dependent transcription regulators. When oxidative stress elevates Fe³⁺ heme concentration, transcriptional repressors such as Rox1p analogs are activated, downregulating genes involved in oxygen-dependent metabolism, including ERG11.

Conversely, a reducing nuclear environment stabilizes Fe²⁺ heme, favoring the activation of heme–Hap1p complexes that upregulate ergosterol biosynthesis. This cyclical oscillation between heme oxidation states acts as a biochemical metronome that synchronizes gene expression with the nuclear redox clock, a phenomenon increasingly recognized as a central element of fungal adaptive physiology.

Comments

Post a Comment

Popular posts from this blog

   At the biochemical level, ERG11 ’s function as a heme-dependent monooxygenase interlocks with the cell’s oxidative balance. Heme fluctuations within the nucleus can alter the activity of heme-responsive transcription factors and chromatin modifiers, introducing a chemical feedback loop between metabolism and genetic variation (Puig & Gutiérrez, 2022). Reactive oxygen species generated by azole stress promote DNA oxidation and base substitution events preferentially within open chromatin domains. This coupling of redox chemistry with mutation formation constitutes a nuclear-scale biochemical evolution engine—one where chemical disequilibrium catalyzes genomic diversity in real time.
Read more

Fungi - Candida auris - Non-Elaborate Posts - Post 2

Genetics and genetic mutations for resistance to fluconazole ERG11 mutations (notably Y132F, K143R) are common contributors to fluconazole resistance; and Cas9 editing showed direct contribution of these alleles to elevated MICs. Additional determinants (TAC1B, efflux pumps, aneuploidy) amplify resistance. Different geographic clades show distinct ERG11 allele frequencies. Genome assemblies reveal structural variation and copy-number differences Resistance evolves under strong antifungal selection in hospitals. Surveillance sequences help track clonal spread and mutation patterns
Read more
In some settings, susceptible-dose dependent (SDD) categorization is used: isolates with intermediate MICs may still respond to higher fluconazole doses, but the presence of ERG11 mutations often reduces the likelihood of clinical success even with dose escalation. ( PMC ) Beyond single substitutions, clinical isolates frequently carry combinations of ERG11 changes plus efflux-regulatory mutations (e.g., TAC1 gain-of-function) that together produce higher MICs and poorer outcomes; thus, sequencing plus expression data can refine prognostic interpretation.
Read more