Topic: Structure and function of the ER

Speaker: Prof. Junjie Hu

Time: 2:00-3:30 PM, 27 April, 2026

Venue: Lecture hall 111, Lynn Library

Abstract:

Structure and function of the endoplasmic reticulum (ER) are tightly linked. The ER is typically an interconnected membrane system with cylindrical tubules and cisternal sheets, from which a variety of vital cellular functions are fulfilled. Through a quantitative proteomic analysis of the tubular ER, we identified 79 proteins that are enriched in these morphological domains. Functional categorization reveals that the tubular ER network are specialized in membrane trafficking, organelle contact and lipid metabolism. We found that shaping proteins regulate COPII-mediated ER export through multiple mechanisms. Through systematic secretome profiling, we identified an ER-resident chaperone that exhibits high secretion propensity due to an evolutionary weakening of the ER retention signal. The extracellular presence of the protein triggers diverse adhesive signals by shielding fibronectin from integrin.

Introduction:

Dr. Junjie Hu is a Principal Investigator at the Institute of Biophysics, Chinese Academy of Sciences, and a recipient of the HHMI International Early Career Scientist Award. He graduated with a bachelor’s degree from Fudan University in 2000 and then pursued his PhD at New York University. After graduation, he continued his postdoctoral research at Harvard Medical School. In 2008, he was appointed as a Professor at the Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, where he established an independent research group focusing on the morphology and functions of the endoplasmic reticulum. In 2013, he joined the National Laboratory of Biomacromolecules at the Institute of Biophysics, Chinese Academy of Sciences, as a principal investigator. He has published over 70 papers in journals such as Science, Cell, Nature Cell Biology, Molecular Cell, etc.