北京大学定量生物学中心

学术报告

题 目: Coupling of the cyanobacterial circadian clock to cell division cycle: mechanisms and functions

报告人: Dr. Chao Ye

School of Life Sciences, University of Warwick, UK

时 间: 11月6日（周三）16:00-17:00

地 点: 吕志和楼B101

主持人: 欧阳颀 教授/曹远胜 研究员

摘要:

In this talk I will address two key questions related to the coupling of the circadian clock and the cell division cycle, using the cyanobacterial circadian clock as a model system. First, what is the molecular mechanism that underlines the circadian control of cell division? Using single-cell fluorescence time-lapse microscopy and mathematical modelling, we showed that the clock continuously orchestrates cell division throughout the day by regulating the localisation of the cell-division scaffolding protein FtsZ, which in turn sets a “timer” for cell division. Second, is the coupling between the circadian clock and cell cycle uni- or bidirectional? Recently we reported that the cyanobacterial circadian clock modulates the expression amplitude of the alternative sigma factor RpoD4, which only pulses at cell division. This pulse amplitude modulation (PAM), analogous to AM radio, represents a new class of circadian regulation. Apart from testing and demonstrating PAM as a broader mechanism for biological clocks, we also observed that deletion and overexpression of RpoD4 modulate the cell size and clock period, suggesting a potential bidirectional coupling between the circadian clock and the cell division cycle in cyanobacteria.

报告人简介：

Chao studied Natural Sciences Tripos at the University of Cambridge from 2012 and was awarded the Bachelor of Arts and Masters of Natural Sciences degrees in 2016. Chao’s doctoral training was conducted at the Sainsbury Laboratory, University of Cambridge and he was supervised by Prof. James CW Locke. During his PhD, Chao investigated the regulatory interactions and dynamics between the circadian clock and sigma factors in the cyanobacterium Synechococcus elongatus PCC 7942, and was awarded the PhD of Biochemistry degree in 2023. After finishing his PhD, Chao joined Dr. Bruno MC Martins’ group at the School of Life Sciences, University of Warwick, where he investigates the circadian regulation of the cell division in cyanobacteria as a Research Fellow.