NO. 89

CIMR Wednesday Lecture Series

Time:

Wednesday, Dec. 3 2025, 4:00 p.m.

Location:

Multi-Function Hall, 2nd Floor, North Basic Research Building

Host:

Pengfei Guo (郭鹏飞)

Chinese Institutes for Medical Research, Beijing

Speaker:

Hong Zhang (张宏)

Professor

Institute of Biophysics, Chinese Academy of Sciences

TITLE:

Dynamic Ca²⁺ Signals Drive Autophagosome Formation

ABSTRACT:

Autophagy, an evolutionarily conserved lysosomal degradation pathway, sustains cellular homeostasis by recycling cytoplasmic material and eliminating cytotoxic threats. The core of this process is the biogenesis of the autophagosome, a double-membraned vesicle that forms through the initiation, expansion, and closure of an isolation membrane. In metazoans, autophagosomes assemble on the endoplasmic reticulum (ER). Pioneering genetic studies in model organisms identified a core autophagy machinery (ATG and EPG genes), and subsequent work revealed that the FIP200 complex—the functional equivalent of the yeast Atg1 complex—translocates to the ER to recruit downstream factors upon autophagy induction. Despite these advances, the fundamental mechanism that initiates the formation of the autophagosome on the ER membrane has remained a central unanswered question in the field.

Our previous research revealed that diverse autophagy stimuli trigger localized Ca²⁺ transients on the outer ER membrane. These ER-localized Ca²⁺ signals trigger the liquid-liquid phase separation of the FIP200 complex. The resultant liquid-like FIP200 condensates associate with the ER, and further mature into functional autophagosome formation sites. In my talk, I will present our recent progress in understanding how these ER Ca²⁺ transients are sustained during autophagy induction and how they are decoded to trigger the assembly of ER-associated FIP200 condensates.

INTRODUCTION OF SPEAKER:

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