International Symposium on Protein and Organelle Lifetime Regulation ( ISPO2025 ): From Turnover Mechanisms to Targeted Control

The International Symposium on Protein and Organelle Lifetime Regulation (ISPO2025) was held on 30 October-2 November 2025 at Nara Kasugano Forum Iraka, Nara, Japan. The meeting was organized by the core members of the Transformative Research Areas (A) project "Shin-Biology Regulated by Protein Lifetime," and brought together 195 participants (150 from Japan and 45 from abroad). The program comprised 11 oral sessions, 16 invited lectures by speakers from overseas, and 83 posters. Topics spanned proteasome-mediated and autophagy-mediated pathways underlying protein and organelle turnover, quantitative technologies to measure these processes with accuracy and depth, and chemical approaches to modulate protein and organelle degradation. The Keiji Tanaka Memorial Session opened the symposium, honoring his legacy in proteasome biology and intracellular proteolysis. Across the meeting, protein and organelle lifetime emerged as measurable and comparable readouts connecting molecular mechanisms to disease-relevant cellular states and therapeutic strategy, while also unifying proteome remodeling, organelle quality control, and drug discovery.