Role of the C-terminal cysteines in virus-like particle formation and oligomerization of the hepatitis E virus ORF2 truncated proteins

Zhenzhen Liu; Nouredine Behloul; Sarra Baha; Wenjuan Wei; Wanru Tao; Tingying Zhang; Wei Li; Ruihua Shi; Jihong Meng

doi:10.1016/j.virol.2020.01.011

Role of the C-terminal cysteines in virus-like particle formation and oligomerization of the hepatitis E virus ORF2 truncated proteins

Virology. 2020 May:544:1-11. doi: 10.1016/j.virol.2020.01.011. Epub 2020 Feb 14.

Authors

Zhenzhen Liu¹, Nouredine Behloul², Sarra Baha³, Wenjuan Wei³, Wanru Tao⁴, Tingying Zhang², Wei Li⁵, Ruihua Shi⁶, Jihong Meng⁷

Affiliations

¹ College of Basic Medicine, Shanghai University of Medicine and Health Sciences, Shanghai, 201318, China; Department of Gastroenterology, Zhongda Hospital, Southeast University, Nanjing, 210009, Jiangsu province, China.
² College of Basic Medicine, Shanghai University of Medicine and Health Sciences, Shanghai, 201318, China.
³ Department of Gastroenterology, Zhongda Hospital, Southeast University, Nanjing, 210009, Jiangsu province, China.
⁴ Laboratory of Nano Biomedicine, Second Military Medical University, Shanghai, 200433, China.
⁵ College of Basic Medicine, Shanghai University of Medicine and Health Sciences, Shanghai, 201318, China; Laboratory of Nano Biomedicine, Second Military Medical University, Shanghai, 200433, China. Electronic address: liwei_dds@163.com.
⁶ Department of Gastroenterology, Zhongda Hospital, Southeast University, Nanjing, 210009, Jiangsu province, China. Electronic address: ruihuashi@126.com.
⁷ College of Basic Medicine, Shanghai University of Medicine and Health Sciences, Shanghai, 201318, China; Department of Gastroenterology, Zhongda Hospital, Southeast University, Nanjing, 210009, Jiangsu province, China. Electronic address: jihongmeng@163.com.

PMID: 32174509
DOI: 10.1016/j.virol.2020.01.011

Abstract

The hepatitis E virus (HEV) ORF2 truncated recombinant proteins can self-assemble into virus-like particles (VLPs) and were used as models to investigate the HEV capsid assembly. However, the structural function of the ORF2 C-terminal domain (C52aa from aa 608 to aa 660) remains unclear. Herein, by analyzing a set of ORF2 truncated proteins expressed in Escherichia coli, we found that the highly conserved C-terminal cysteines play a crucial role in the oligomerization of the truncated ORF2 proteins and in their assembly into VLPs, through the formation of dimer-dimer disulfide bonds; and the treatment of native HEV particles with dithiothreitol (DTT) induced the disassembly of the viral capsid, suggesting that the disulfide bonding is required for stabilizing the native HEV capsid. The present study sheds light on the structural role of the C-terminal region of the HEV capsid protein and contributes to the full understating of the viral capsid assembly process.

Keywords: Capsid assembly; Disulfide bond; Hepatitis E virus; Virus-like particle.

Publication types

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

MeSH terms

Amino Acid Sequence
Animals
Dithiothreitol / pharmacology
Escherichia coli
Gene Expression Regulation, Viral
Hepatitis E virus / genetics
Hepatitis E virus / metabolism*
Viral Proteins / chemistry
Viral Proteins / genetics*
Virus Assembly / physiology*

Substances

ORF2 protein, Hepatitis E virus
Viral Proteins
Dithiothreitol