Mitochondria–ER contact sites (MERCS) in the cell cycle: molecular architecture and functional remodeling across cellular states (opens in new tab)

Mitochondria–endoplasmic reticulum (ER) contact sites (MERCS) are nanoscopic, dynamic platforms integrating metabolism, signaling, and stress responses to regulate cell fate. These nanoscopic interfaces remodel continuously to meet the demands of proliferating, quiescent, and senescent cells. We synthesize evidence that MERCS actively coordinate local Ca2+ signaling, non-vesicular lipid transfer, and proteostasis to shape mitochondrial function and cellular homeostasis. We discuss how MERCS a...