{
  "id": 18605318,
  "title": "Starve, stress, and mate: Activation of the CCAAT-Binding complex overrides sterility of mating-type heterozygous Candida albicans",
  "url": "https://urgent.news/2026/11/06/starve-stress-and-mate-activation-of-the-ccaat-binding-complex",
  "topic": "science",
  "section": "Science",
  "published": "2026-11-06T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.11.05.764546v1?rss=1"
  },
  "original_language": "en",
  "account": "Recent research has uncovered a crucial molecular mechanism that enables the human fungal pathogen Candida albicans to bypass genetic sterility in mating-type heterozygous (MTLa/) diploid strains. Under typical conditions, a1-2 repressor actively blocks mating competency in these strains. However, researchers have identified the highly conserved CCAAT-binding complex (CBC) as the key developmental hub that integrates environmental stress to unlock this genetic barrier.\n\nUsing proteomic mapping (ChIP-SICAP) and transcriptomics (RNA-Seq), scientists defined the regulatory network of the core CBC subunit Hap5. They found that hyperactivation of the CBC system overrides the a1-2 repressor, allowing sterile MTLa/ strains to initiate a mating-competence program. This activation results in a white-to-opaque phenotypic switch, a critical step in the reproductive process.\n\nNotably, the CBC-mediated transition is antagonized by the iron-regulatory partner Hap43. However, the CBC's ability to bypass genetic constraints on sexual reproduction is strictly dependent on physical interaction at the chromatin level with Cap1, the master regulator of the oxidative stress response. Crucially, this developmental transition is triggered by metabolic starvation (glucose and iron limitation) and oxidative stress.\n\nThe findings of this study provide a mechanistic basis for how C. albicans generates genetic diversity under hostile host conditions, by bypassing genetic constraints on sexual reproduction. By coupling metabolic starvation and oxidative stress to a core reproductive program through the CBC and Cap1, this pathogen is able to overcome its genetic sterility and adapt to challenging environments.",
  "summary": "Sexual reproduction in the human fungal pathogen Candida albicans is typically restricted by a strict genetic lock: the a1-2 repressor present in standard mating-type heterozygous (MTLa/) diploid strains, which actively represses mating competency. While severe environmental pressures are known to influence fungal development, the molecular mechanisms that allow cells to override this genetic…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}