In the afternoon of April 14, 2017, Dr. Junjie Hu, the Principle Investigator in The Institute of Biophysics, Chinese Academy of Science, gave a lecture on “The proteome of tubular endoplasmic reticulum” as part of ShanghaiTech’s Life Science Seminar Series.
Professor Junjie Hu and his lab mainly focus on the formation mechanisms and the functions of tubular endoplasmic reticulum (ER), which is a critical and morphologically unique part of the ER. The network of tubular ER is shaped by the reticulons and REEPs/Yop1p that generate tubules by inducing high membrane curvature, and the dynamin-like GTPases atlastin and Sey1p/RHD3 that connect tubules via membrane fusion. ER serves many functions, including protein synthesis, protein quality control, lipid synthesis and membrane contact. However, the specific functions of tubular ER domain are not clear.
Junjie Hu et al. isolated the proteome of tubular endoplasmic reticulum from Saccharomyces cerevisiae by classical cell fractionation and immunoprecipitation of Flag-tagged Yop1p, which specifically localizes to ER. In quantitative comparisons of tubule-derived and total microsomes, they identified 79 proteins that were enriched in the ER tubules. Functional categorization of the list of proteins revealed that the tubular ER may be involved in membrane trafficking, lipid metabolism, organelle contact, and stress sensing. These findings suggest specific roles of the tubular ER network and provide important tools for further functional studies of ER tubules and even other organelles. Furthermore, Dr. Junjie Hu also shared us with the new research progress of his lab on the functions of HT008, which was one of the members on the list of identified 79 proteins. 