{
  "id": 6178241,
  "title": "Dynamic Filament Assembly Regulates the Prolyl Aminopeptidase Activity of Plant Immune Protein DM3",
  "url": "https://urgent.news/2026/09/07/dynamic-filament-assembly-regulates-the-prolyl-aminopeptidase",
  "topic": "science",
  "section": "Science",
  "published": "2026-09-07T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.09.03.749275v1?rss=1"
  },
  "original_language": "en",
  "account": "Proline aminopeptidase DM3, a component of alpha/beta hydrolase DANGEROUS MIX 3 (DM3), plays a role in stress resilience in Arabidopsis thaliana. Its activity is essential for salt and drought tolerance, but not for immune response. The molecular mechanism behind this regulation has been a mystery. Researchers have now discovered that DM3 undergoes dynamic and reversible assembly into higher-order filaments, a process that is sensitive to salt levels. Cryo-electron microscopy (EM) revealed that this filament formation occurs due to rearrangements of a planar hexamer into a tilted hexameric configuration. Crucially, within these filaments, one of the catalytic residues is misaligned, disrupting the enzyme's geometry and rendering it inactive. This study establishes that filament assembly serves as a mechanism to keep DM3 inactive, suggesting that the shift between different oligomeric states enables DM3 to coordinate its roles in both biotic and abiotic stress responses.",
  "summary": "The alpha/beta hydrolase DANGEROUS MIX 3 (DM3), a proline aminopeptidase in Arabidopsis thaliana, contributes to stress resilience through both metabolic regulation and immune signaling. Its functions are partitioned within its oligomeric structure as a trimer-of-dimers, in which the immune regulatory switch resides at the dimer interface. While the enzymatic activity of DM3 is not necessary for…",
  "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."
}