Discovery of FRAG-i: a small molecule inhibitor of Drp1 that modulates mitochondrial fission


ATEŞOĞLU Ş., Çataltepe S. N., Bardakcı E., Aldogan E. H., Yorgancioglu Budak G., Bektaş M., ...More

Mitochondrion, vol.90, 2026 (SCI-Expanded, Scopus) identifier identifier

  • Publication Type: Article / Article
  • Volume: 90
  • Publication Date: 2026
  • Doi Number: 10.1016/j.mito.2026.102162
  • Journal Name: Mitochondrion
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Chemical Abstracts Core, EMBASE, MEDLINE
  • Keywords: Drp1, Fission, Mitochondrial dynamics, Small molecule inhibitors
  • Istanbul University-Cerrahpasa Affiliated: No

Abstract

Mitochondrial dynamics, regulated by the balance of fission and fusion, are essential for cellular homeostasis, and their disruption—particularly via excessive Drp1-dependent fission—contributes to cancer and other pathologies. Current Drp1 inhibitors lack specificity or exhibit off-target toxicity, highlighting the need for safer alternatives. Here, we identify FRAG-i, a small-molecule Drp1 inhibitor discovered through multi-stage virtual screening and molecular dynamics refinement of a 3.5-million-compound library. FRAG-i binds the Drp1 GTPase domain with high affinity (Kd = 732.4 ± 4.2 nM) and increases Drp1 thermal stability in recombinant and cellular assays. Functionally, FRAG-i selectively suppresses mitochondrial fission in A549 lung carcinoma cells while sparing the fused networks of non-cancerous BEAS-2B epithelial cells. FRAG-i preserves mitochondrial membrane potential, ATP levels, and redox balance without cytotoxicity, and modulates Drp1, MiD49, and Mfn2 expression in a context-dependent manner. These results establish FRAG-i as a selective, non-toxic Drp1 inhibitor with potential for further therapeutic development.