{
  "id": 19231909,
  "title": "Core MCC of Arabidopsis thaliana: structural dissection provides new insights into Mad2, BubR1 and CDC20",
  "url": "https://urgent.news/2026/11/09/core-mcc-of-arabidopsis-thaliana-structural-dissection-provides-new",
  "topic": "science",
  "section": "Science",
  "published": "2026-11-09T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.11.06.764920v1?rss=1"
  },
  "original_language": "en",
  "account": "The spindle assembly checkpoint (SAC) mechanism, essential for accurate chromosome segregation, is governed by the mitotic checkpoint complex (MCC). Researchers have now dissected the structural components of the core MCC26 in Arabidopsis thaliana, uncovering new insights into the proteins CDC20, BubR1 (BMF2), and Mad2. Utilizing bigBac, chemical crosslinking, mass spectrometry, and structural analysis, the team identified 53 nonredundant protein-protein interactions (PPIs) among these key components. The crosslinks revealed a variety of binding sites within the proteins, including the beta-propeller of AtCDC20, tetratricopeptide domain, and KEN boxes in AtBubR1 and a novel KET box. AtMad2 exhibited an additional Horma domain. The interactions among the three proteins suggest a regulatory hierarchy that could influence SAC signaling. Notably, only interactions within the Mad2 tetramer, comprising two dimers, were identified, contrasting with other eukaryotes where interactions with AtBub1 (BMF1) and AtBub3:1 were not detected. These findings provide a structural foundation for core MCC formation in A. thaliana and offer novel perspectives on the roles of CDC20, BubR1, and Mad2 within the SAC.",
  "summary": "The spindle assembly checkpoint (SAC) is a mechanism executed mainly by the mitotic checkpoint complex (MCC) to monitor the anchoring of mitotic spindle microtubules to ensure correct chromosome segregation. Although knowledge of protein-protein interactions in the plant cell cycle has progressed in recent years, information on the SAC mechanism in this context remains scarce. Here, we used…",
  "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."
}