{
  "id": 6283172,
  "title": "The Greatwall/PP2A-B55α axis remodels the G2/M boundary and shapes cellular dependence on PKMYT1",
  "url": "https://urgent.news/2026/09/08/the-greatwall-pp2a-b55-axis-remodels-the-g2-m-boundary-and-shapes",
  "topic": "science",
  "section": "Science",
  "published": "2026-09-08T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.09.04.749407v1?rss=1"
  },
  "original_language": "en",
  "account": "The G2/M transition and mitotic exit rely on a feedback loop involving CDK1, Greatwall kinase, and the PP2A-B55 phosphatase. Disruptions in these regulators cause cellular dysfunction, genomic instability, and cancer-like traits. However, the interaction of these factors and their context-dependence remain unknown. This study examines how the combined perturbation of CDK1, Greatwall, and PP2A-B55 affects cell-cycle control in non-transformed RPE-1 and cancerous HeLa cells. The researchers find that PP2A-B55 acts as a G2/M repressor in cancer cells, working alongside PKMYT1 and WEE1 to prevent premature mitosis. When PP2A-B55 activity is reduced and Greatwall expression is increased, there is heightened sensitivity to the PKMYT1-specific drug RP-6306 and moderate sensitivity to the WEE1-specific adavosertib in cancer cells. This differential sensitivity reveals a functional distinction between WEE1 and PKMYT1 in S- and G2-phase regulation. The findings highlight the cell-type-specific roles of CDK1, Greatwall, and PP2A-B55 in cell-cycle regulation and suggest G2/M plasticity as a potential vulnerability for targeting in PKMYT1-mediated therapies.",
  "summary": "The switch-like G2/M transition and mitotic exit depend on a feedback loop comprising CDK1, Greatwall kinase, and the PP2A-B55 phosphatase. Monogenic disruptions of these regulators impair cellular functions, drive genomic instability, and promote cancer-associated characteristics. Yet how perturbations of this feedback loop interact, and whether their effects depend on cellular context, remain…",
  "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."
}