Distinct roles and actions of protein disulfide isomerase family enzymes in catalysis of nascent-chain disulfide bond formation

iScience

Kenji Inaba¹  Teru Ogura²  Kodai Machida³  Tadayoshi Murakawa⁴  Kentaro Noi⁵  Hiroaki Imataka⁶  Chihiro Hirayama⁷  Masaki Okumura⁷ 

[1] Faculty of Life Sciences, Kumamoto University, Kumamoto, Kumamoto 862-0973, Japan;Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan;Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2280, Japan;Graduate School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Kanagawa, 226-8503, Japan;Institute for NanoScience Design, Osaka University, Toyonaka, Osaka 560-8531, Japan;Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Kumamoto 860-0811, Japan;Institute of Multidisciplinary Research for Advanced Materials, Katahira 2-1-1, Aoba-ku, Tohoku University, Sendai, Miyagi 980-8577, Japan;

关键词: Cell Biology;    Molecular Biology;    Structural Biology;   

DOI  :  

来源: DOAJ

【 摘 要 】

Summary: The mammalian endoplasmic reticulum (ER) harbors more than 20 members of the protein disulfide isomerase (PDI) family that act to maintain proteostasis. Herein, we developed an in vitro system for directly monitoring PDI- or ERp46-catalyzed disulfide bond formation in ribosome-associated nascent chains of human serum albumin. The results indicated that ERp46 more efficiently introduced disulfide bonds into nascent chains with a short segment exposed outside the ribosome exit site than PDI. Single-molecule analysis by high-speed atomic force microscopy further revealed that PDI binds nascent chains persistently, forming a stable face-to-face homodimer, whereas ERp46 binds for a shorter time in monomeric form, indicating their different mechanisms for substrate recognition and disulfide bond introduction. Thus, ERp46 serves as a more potent disulfide introducer especially during the early stages of translation, whereas PDI can catalyze disulfide formation when longer nascent chains emerge out from ribosome.

【 授权许可】

Unknown