Rag GTPases and mTORC1 regulate intestinal stem cell activity in response to nutrient availability.

Inhibition of Rag GTPases and mTORC1 in enterocytes increases intestinal stem cell activity via distinct pathways, with Rag GTPases affecting Mitf and mTORC1 acting independently.

• Why it matters: Understanding how nutrient signals regulate intestinal stem cells is crucial for insights into tissue homeostasis and potential disease interventions, yet the mechanisms are not fully known.
• What they did: The study used genetic inhibition of Rag GTPases and mTORC1 in Drosophila enterocytes, observing increased ISC proliferation and differentiation through the Upd3-JAK-STAT pathway, with different underlying mechanisms.
• The result: Findings demonstrate a nutrient-sensing network involving Rag GTPases and mTORC1 that modulates ISC activity, highlighting how nutrient availability influences intestinal regeneration and homeostasis.