Identification of ERAD components essential for dislocation of the null Hong Kong variant of α-1-antitrypsin (NHK)

Yongwang Zhong; Hang Shen; Ye Wang; Yili Yang; Peixin Yang; Shengyun Fang

doi:10.1016/j.bbrc.2015.01.133

Identification of ERAD components essential for dislocation of the null Hong Kong variant of α-1-antitrypsin (NHK)

Biochem Biophys Res Commun. 2015 Mar 6;458(2):424-8. doi: 10.1016/j.bbrc.2015.01.133. Epub 2015 Feb 7.

Authors

Yongwang Zhong¹, Hang Shen², Ye Wang², Yili Yang³, Peixin Yang⁴, Shengyun Fang⁵

Affiliations

¹ Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA. Electronic address: yzhong@umaryland.edu.
² Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
³ Department of Colorectal Cancer and Center for Medical Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 20025, China.
⁴ Department of Obstetrics, Gynecology & Reproductive Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
⁵ Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA. Electronic address: sfang@umaryland.edu.

PMID: 25660456
DOI: 10.1016/j.bbrc.2015.01.133

Abstract

Misfolded proteins or orphan subunits of protein complexes are removed from the endoplasmic reticulum (ER) by ER-associated degradation (ERAD). ERAD requires dislocation, also known as retrotranslocation, of those unwanted proteins from the ER lumen to the cytosol for destruction by the proteasomes. Over one hundred ERAD component proteins have been identified but their role in dislocation remain poorly understood. Here we assessed the requirement of ERAD components for dislocation of NHK in live cells using our recently developed dislocation-induced reconstituted GFP (drGFP) assay. RNAi revealed that 12 out of 21 ERAD components examined are required for efficient dislocation of NHK among which Hrd1, Sel1L, GRP94 and p97/VCP are critically required. In addition, knockdown of 7 of the 21 components enhanced NHK dislocation. This study uncovers a complex functional network of proteins required for NHK dislocation.

Keywords: Dislocation/retrotranslocation; ERAD; Hrd1; Sel1L; drGFP; p97/VCP.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Endoplasmic Reticulum / metabolism*
Endoplasmic Reticulum-Associated Degradation / physiology*
HeLa Cells
Hong Kong
Humans
alpha 1-Antitrypsin / metabolism*

Substances

SERPINA1 protein, human
alpha 1-Antitrypsin