PLEASE NOTE THE UNUSUAL DAY. Masaaki Komatsu, PhD - "Proteostasis Governed by Autophagy and the UFM1 System"

  • When Jun 12, 2026 from 12:00 PM to 01:15 PM (Europe/Berlin / UTC200)
  • Where Tigem Auditorium Angelo Maramai
  • Contact Name
  • Contact Phone 3392055239
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PLEASE NOTE THE UNUSUAL DAY. Masaaki Komatsu, PhD - "Proteostasis Governed by Autophagy and the UFM1 System"

Masaaki Komatsu, PhD
Department of Physiology
Juntendo University Graduate School of Medicine
Tokyo, Japan

Short CV

Abstract
Proteostasis is safeguarded by multiple quality-control pathways, among which selective autophagy and the UFM1 system provide distinct yet complementary modes of regulation. In the first part of this talk, I will discuss how p62/SQSTM1-mediated selective autophagy is controlled through phosphorylation-dependent remodeling of p62 condensates. TBK1-mediated phosphorylation at Ser403 acts as a molecular rheostat that miniaturizes and gels p62 bodies, thereby enhancing their capacity to capture LC3-positive membranes and accelerate autophagic clearance of ubiquitinated proteins. This modification is counteracted by PP2A holoenzymes recruited via KEAP1. Phosphorylation-mimetic knock-in cells and mice accumulate compact, gel-like p62 condensates, demonstrating that this material-state switch operates across cellular and organismal levels to maintain proteostasis.

In the second part, I will present our findings on how proteostasis is further secured by a finely tuned cycle of UFM1 conjugation and deconjugation within the endoplasmic reticulum–associated ribosome quality-control (ER-RQC) pathway. The ER-anchored UFSP2–ODR4 complex functions as a spatially restricted deUFMylation module for RPL26. Disruption of this module—or excessive UFM1 conjugation caused by biallelic UFC1 mutations—results in hyper-UFMylation, impaired ER-RQC, and neurodevelopmental defects. Together, these studies highlight how autophagy and the UFM1 system jointly govern neuronal proteostasis.