Expression Level of Small Envelope Protein in Addition to Sequence Divergence inside Its Major Hydrophilic Region Contributes to More Efficient Surface Antigen Secretion by Hepatitis B Virus Subgenotype D2 than Subgenotype A2

Expression Level of Small Envelope Protein in Addition to Sequence Divergence inside Its Major Hydrophilic Region Contributes to More Efficient Surface Antigen Secretion by Hepatitis B Virus Subgenotype D2 than Subgenotype A2

Hepatitis B surface antigen (HBsAg) promotes persistent hepatitis B virus (HBV) infection. It primarily corresponds to small (S) envelope protein secreted as subviral particles. We previously found that genotype D clones expressed less S protein than genotype A clones but showed higher extracellular...

Full description

Bibliographic Details
Main Authors: Qianru Wang, Shuwen Fu, Jing Zhang, Quan Yuan, Jisu Li, Ningshao Xia, Yu-Mei Wen, Yongxiang Wang, Shuping Tong
Format: Article
Language:English
Published: MDPI AG 2020-09-01
Series:Viruses
Subjects:
hepatitis B virus
hepatitis B surface antigen
small envelope protein
large envelope protein
genotype
mutation
Online Access:https://www.mdpi.com/1999-4915/12/9/967
id doaj-4ab206e92d44453c81786be44cd2d852
record_format Article
spelling doaj-4ab206e92d44453c81786be44cd2d8522020-11-25T03:35:58ZengMDPI AGViruses1999-49152020-09-011296796710.3390/v12090967Expression Level of Small Envelope Protein in Addition to Sequence Divergence inside Its Major Hydrophilic Region Contributes to More Efficient Surface Antigen Secretion by Hepatitis B Virus Subgenotype D2 than Subgenotype A2Qianru Wang0Shuwen Fu1Jing Zhang2Quan Yuan3Jisu Li4Ningshao Xia5Yu-Mei Wen6Yongxiang Wang7Shuping Tong8Department of Pathobiology, Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, ChinaDepartment of Pathobiology, Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, ChinaDepartment of Pathobiology, Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, ChinaState Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102 ChinaLiver Research Center, Rhode Island Hospital and Warren Alpert Medical School of Brown University, Providence, RI 02903, USAState Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102 ChinaDepartment of Pathobiology, Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, ChinaDepartment of Pathobiology, Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, ChinaDepartment of Pathobiology, Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, ChinaHepatitis B surface antigen (HBsAg) promotes persistent hepatitis B virus (HBV) infection. It primarily corresponds to small (S) envelope protein secreted as subviral particles. We previously found that genotype D clones expressed less S protein than genotype A clones but showed higher extracellular/intracellular ratio of HBsAg suggesting more efficient secretion. The current study aimed to characterize the underlying mechanism(s) by comparing a subgenotype A2 clone (geno5.4) with a subgenotype D2 clone (geno1.2). Five types of full-length or subgenomic constructs were transfected to Huh7 cells at different dosage. HBsAg was quantified by enzyme linked immunosorbent assay while envelope proteins were detected by Western blot. We found that ratio of extracellular/intracellular HBsAg decreased at increasing amounts of DNA transfected. Conflicting findings from two types of subgenomic construct confirmed stronger secretion inhibitory effect of the genotype D-derived large envelope protein. Chimeric constructs followed by site-directed mutagenesis revealed geno1.2 specific V118/T127 and F161/A168 in the S protein as promoting and inhibitory of HBsAg secretion, respectively. In conclusion, more efficient HBsAg secretion by subgenotype D2 than subgenotype A2 is attributed to lower level of S protein expression in addition to V118 and T127 in S protein, although its F161 and A168 sequences rather reduce HBsAg secretion.https://www.mdpi.com/1999-4915/12/9/967hepatitis B virushepatitis B surface antigensmall envelope proteinlarge envelope proteingenotypemutation
collection DOAJ
language English
format Article
sources DOAJ
author Qianru Wang
Shuwen Fu
Jing Zhang
Quan Yuan
Jisu Li
Ningshao Xia
Yu-Mei Wen
Yongxiang Wang
Shuping Tong
spellingShingle Qianru Wang
Shuwen Fu
Jing Zhang
Quan Yuan
Jisu Li
Ningshao Xia
Yu-Mei Wen
Yongxiang Wang
Shuping Tong
Expression Level of Small Envelope Protein in Addition to Sequence Divergence inside Its Major Hydrophilic Region Contributes to More Efficient Surface Antigen Secretion by Hepatitis B Virus Subgenotype D2 than Subgenotype A2
Viruses
hepatitis B virus
hepatitis B surface antigen
small envelope protein
large envelope protein
genotype
mutation
author_facet Qianru Wang
Shuwen Fu
Jing Zhang
Quan Yuan
Jisu Li
Ningshao Xia
Yu-Mei Wen
Yongxiang Wang
Shuping Tong
author_sort Qianru Wang
title Expression Level of Small Envelope Protein in Addition to Sequence Divergence inside Its Major Hydrophilic Region Contributes to More Efficient Surface Antigen Secretion by Hepatitis B Virus Subgenotype D2 than Subgenotype A2
title_short Expression Level of Small Envelope Protein in Addition to Sequence Divergence inside Its Major Hydrophilic Region Contributes to More Efficient Surface Antigen Secretion by Hepatitis B Virus Subgenotype D2 than Subgenotype A2
title_full Expression Level of Small Envelope Protein in Addition to Sequence Divergence inside Its Major Hydrophilic Region Contributes to More Efficient Surface Antigen Secretion by Hepatitis B Virus Subgenotype D2 than Subgenotype A2
title_fullStr Expression Level of Small Envelope Protein in Addition to Sequence Divergence inside Its Major Hydrophilic Region Contributes to More Efficient Surface Antigen Secretion by Hepatitis B Virus Subgenotype D2 than Subgenotype A2
title_full_unstemmed Expression Level of Small Envelope Protein in Addition to Sequence Divergence inside Its Major Hydrophilic Region Contributes to More Efficient Surface Antigen Secretion by Hepatitis B Virus Subgenotype D2 than Subgenotype A2
title_sort expression level of small envelope protein in addition to sequence divergence inside its major hydrophilic region contributes to more efficient surface antigen secretion by hepatitis b virus subgenotype d2 than subgenotype a2
publisher MDPI AG
series Viruses
issn 1999-4915
publishDate 2020-09-01
description Hepatitis B surface antigen (HBsAg) promotes persistent hepatitis B virus (HBV) infection. It primarily corresponds to small (S) envelope protein secreted as subviral particles. We previously found that genotype D clones expressed less S protein than genotype A clones but showed higher extracellular/intracellular ratio of HBsAg suggesting more efficient secretion. The current study aimed to characterize the underlying mechanism(s) by comparing a subgenotype A2 clone (geno5.4) with a subgenotype D2 clone (geno1.2). Five types of full-length or subgenomic constructs were transfected to Huh7 cells at different dosage. HBsAg was quantified by enzyme linked immunosorbent assay while envelope proteins were detected by Western blot. We found that ratio of extracellular/intracellular HBsAg decreased at increasing amounts of DNA transfected. Conflicting findings from two types of subgenomic construct confirmed stronger secretion inhibitory effect of the genotype D-derived large envelope protein. Chimeric constructs followed by site-directed mutagenesis revealed geno1.2 specific V118/T127 and F161/A168 in the S protein as promoting and inhibitory of HBsAg secretion, respectively. In conclusion, more efficient HBsAg secretion by subgenotype D2 than subgenotype A2 is attributed to lower level of S protein expression in addition to V118 and T127 in S protein, although its F161 and A168 sequences rather reduce HBsAg secretion.
topic hepatitis B virus
hepatitis B surface antigen
small envelope protein
large envelope protein
genotype
mutation
url https://www.mdpi.com/1999-4915/12/9/967
work_keys_str_mv AT qianruwang expressionlevelofsmallenvelopeproteininadditiontosequencedivergenceinsideitsmajorhydrophilicregioncontributestomoreefficientsurfaceantigensecretionbyhepatitisbvirussubgenotyped2thansubgenotypea2
AT shuwenfu expressionlevelofsmallenvelopeproteininadditiontosequencedivergenceinsideitsmajorhydrophilicregioncontributestomoreefficientsurfaceantigensecretionbyhepatitisbvirussubgenotyped2thansubgenotypea2
AT jingzhang expressionlevelofsmallenvelopeproteininadditiontosequencedivergenceinsideitsmajorhydrophilicregioncontributestomoreefficientsurfaceantigensecretionbyhepatitisbvirussubgenotyped2thansubgenotypea2
AT quanyuan expressionlevelofsmallenvelopeproteininadditiontosequencedivergenceinsideitsmajorhydrophilicregioncontributestomoreefficientsurfaceantigensecretionbyhepatitisbvirussubgenotyped2thansubgenotypea2
AT jisuli expressionlevelofsmallenvelopeproteininadditiontosequencedivergenceinsideitsmajorhydrophilicregioncontributestomoreefficientsurfaceantigensecretionbyhepatitisbvirussubgenotyped2thansubgenotypea2
AT ningshaoxia expressionlevelofsmallenvelopeproteininadditiontosequencedivergenceinsideitsmajorhydrophilicregioncontributestomoreefficientsurfaceantigensecretionbyhepatitisbvirussubgenotyped2thansubgenotypea2
AT yumeiwen expressionlevelofsmallenvelopeproteininadditiontosequencedivergenceinsideitsmajorhydrophilicregioncontributestomoreefficientsurfaceantigensecretionbyhepatitisbvirussubgenotyped2thansubgenotypea2
AT yongxiangwang expressionlevelofsmallenvelopeproteininadditiontosequencedivergenceinsideitsmajorhydrophilicregioncontributestomoreefficientsurfaceantigensecretionbyhepatitisbvirussubgenotyped2thansubgenotypea2
AT shupingtong expressionlevelofsmallenvelopeproteininadditiontosequencedivergenceinsideitsmajorhydrophilicregioncontributestomoreefficientsurfaceantigensecretionbyhepatitisbvirussubgenotyped2thansubgenotypea2
_version_ 1724552189363355648

Similar Items