IMM & CLS Research Seminar

Title：Mechanisms of collagen secretion from the endoplasmic reticulum

Speaker：Kota Saito, Ph.D.

Assistant Professor,

Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences,

University of Tokyo, Japan

Time：2015年9月24日（星期四）下午4:00-5:00

Place：北京大学英杰交流中心306会议室

Host：北京大学分子医学研究所  陈晓伟 (Tel. 6276-8919)

Abstract: Mechanisms for exporting different-sized cargo from the endoplasmic reticulum (ER) remain poorly understood. COPII-coated vesicles, which transport secretory cargoes from the ER to the Golgi apparatus, are typically 80~90 nm in diameter. However, several cargo molecules including collagens form structures that are too large to be accommodated by these vesicles, but their secretion still requires COPII proteins.

We have identified cargo receptor complex (cTAGE5/TANGO1/Sec12) specialized for collagen VII export from the ER. TANGO1’s luminal SH3 domain directly interacts with collagen VII, and Proline-Rich sequences of both cTAGE5 and TANGO1 bind to the inner layer of COPII proteins, Sec23/24. Moreover, cTAGE5 recruits Sec12, a guanine-nucleotide factor for Sar1 GTPase to the ER exit sites and this recruitment is required for collagen VII secretion. Thus, large cargo secretion seems to be achieved by specialized factors, which modulate the process of conventional COPII-dependent vesicle formation.

I would also like to discuss the other recent advances provided by other groups and us on the large cargo secretion.

欢迎各位老师同学积极参加！