Fungi - Candida albicans - Research News, Data, Publications & Aproaches - ERG11 Mutations - Telomeres - Sub-Telomeric Structures - Chromatin Landscape - Nuclear Biology & Nuclear Chemistry Aproaches - Redox–Chromatin Coupling - Non-Elaborate Posts - Post 3

 

 Oxidative stress, generated either by host immune defenses or azole exposure, penetrates the nuclear microenvironment as both a damaging and regulatory signal. Reactive oxygen species (ROS) oxidize cysteine residues within histone-modifying enzymes, transiently inhibiting deacetylases while activating specific demethylases such as JmjC-domain proteins, which require Fe(II) and α-ketoglutarate as cofactors. This redox perturbation leads to histone H3K9 demethylation, chromatin relaxation, and upregulation of ERG11. Hence, the nucleus acts as a redox sensor: chemical electrons determine the transcriptional output, and the genomic defense system responds not with simple repair but with transcriptional adaptation.

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