scholarly journals Heparan Sulfate Proteoglycans Are Required for Cellular Binding of the Hepatitis E Virus ORF2 Capsid Protein and for Viral Infection

2009 ◽  
Vol 83 (24) ◽  
pp. 12714-12724 ◽  
Author(s):  
Manjula Kalia ◽  
Vivek Chandra ◽  
Sheikh Abdul Rahman ◽  
Deepak Sehgal ◽  
Shahid Jameel
Keyword(s):  
Cell Surface ◽  
Heparan Sulfate ◽  
Capsid Protein ◽  
Marked Reduction ◽  
Electrostatic Interactions ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Heparan Sulfate Proteoglycans ◽  
Productive Infection ◽  
Target Cells

ABSTRACT The hepatitis E virus (HEV), a nonenveloped RNA virus, is the causative agent of hepatitis E. The mode by which HEV attaches to and enters into target cells for productive infection remains unidentified. Open reading frame 2 (ORF2) of HEV encodes its major capsid protein, pORF2, which is likely to have the determinants for virus attachment and entry. Using an ∼56-kDa recombinant pORF2 that can self-assemble as virus-like particles, we demonstrated that cell surface heparan sulfate proteoglycans (HSPGs), specifically syndecans, play a crucial role in the binding of pORF2 to Huh-7 liver cells. Removal of cell surface heparan sulfate by enzymatic (heparinase) or chemical (sodium chlorate) treatment of cells or competition with heparin, heparan sulfate, and their oversulfated derivatives caused a marked reduction in pORF2 binding to the cells. Syndecan-1 is the most abundant proteoglycan present on these cells and, hence, plays a key role in pORF2 binding. Specificity is likely to be dictated by well-defined sulfation patterns on syndecans. We show that pORF2 binds syndecans predominantly via 6-O sulfation, indicating that binding is not entirely due to random electrostatic interactions. Using an in vitro infection system, we also showed a marked reduction in HEV infection of heparinase-treated cells. Our results indicate that, analogous to some enveloped viruses, a nonenveloped virus like HEV may have also evolved to use HSPGs as cellular attachment receptors.

scholarly journals Membrane anchoring of heparan sulfate proteoglycans by phosphatidylinositol and kinetics of synthesis of peripheral and detergent-solubilized proteoglycans in Schwann cells.

1989 ◽  
Vol 108 (5) ◽  
pp. 1891-1897 ◽  
Author(s):  
D J Carey ◽  
D M Evans
Keyword(s):  
Cell Surface ◽  
Heparan Sulfate ◽  
Schwann Cells ◽  
Electrostatic Interactions ◽  
Heparan Sulfate Proteoglycans ◽  
Membrane Bound ◽  
Covalently Linked ◽  
Mode Of Attachment ◽  
Membrane Anchoring ◽  
Kinetics Of

Previous studies have shown that Schwann cells synthesize both peripheral and integral hydrophobic cell surface heparan sulfate proteoglycans (HSPGs). The experiments reported here were undertaken to investigate the mode of attachment of these proteins to the cell surface and their potential interrelationship. The binding of the hydrophobic HSPGs to membranes appears to be via covalently linked phosphatidylinositol based on the observation that incubation of the detergent-solubilized protein with purified phosphatidylinositol-specific phospholipase C significantly reduces the ability of the HSPGs to associate with phospholipid vesicles in a reconstitution assay. The peripherally associated HSPGs were released from the cells by incubation in the presence of heparin (10 mg/ml), 10 mM phytic acid (inositol hexaphosphate), or 2 M NaCl. These treatments also solubilized basement membrane HSPGs synthesized by the Schwann cells. These data suggest that the peripheral HSPGs are bound to the surface by electrostatic interactions. The peripheral and hydrophobic HSPGs were identical in overall size, net charge, length of glycosaminoglycan chains, and patterns of N-sulfation. To determine whether the peripheral HSPGs were derived from the membrane-bound form by cleavage of the membrane anchor, we examined the kinetics of synthesis and degradation of the two forms of HSPGs. The results obtained indicated the existence of two pools of detergent-solubilized HSPG with fast (t1/2 = 6 h) and slow (t1/2 = 55 h) turnover kinetics. The data were consistent with a model in which the peripheral HSPGs were derived from the slowly turning over pool of detergent-solubilized HSPGs.

scholarly journals Extracellular distribution of diffusible growth factors controlled by heparan sulfate proteoglycans during mammalian embryogenesis

2014 ◽  
Vol 369 (1657) ◽  
pp. 20130545 ◽  
Author(s):  
Isao Matsuo ◽  
Chiharu Kimura-Yoshida
Keyword(s):  
Growth Factors ◽  
Cell Surface ◽  
Heparan Sulfate ◽  
Cell Fate ◽  
Heparan Sulfate Proteoglycans ◽  
Target Cells ◽  
Dependent Manner ◽  
Mammalian Development ◽  
Morphogenetic Protein ◽  
And Control

During mouse embryogenesis, diffusible growth factors, i.e. fibroblast growth factors, Wnt, bone morphogenetic protein and Hedgehog family members, emanating from localized areas can travel through the extracellular space and reach their target cells to specify the cell fate and form tissue architectures in coordination. However, the mechanisms by which these growth factors travel great distances to their target cells and control the signalling activity as morphogens remain an enigma. Recent studies in mice and other model animals have revealed that heparan sulfate proteoglycans (HSPGs) located on the cell surface (e.g. syndecans and glypicans) and in the extracellular matrix (ECM; e.g. perlecan and agrin) play crucial roles in the extracellular distribution of growth factors. Principally, the function of HSPGs depends primarily on the fine features and localization of their heparan sulfate glycosaminoglycan chains. Cell-surface-tethered HSPGs retain growth factors as co-receptors and/or endocytosis mediators, and enzymatic release of HSPGs from the cell membrane allows HSPGs to transport or move multiple growth factors. By contrast, ECM-associated HSPGs function as a reservoir or barrier in a context-dependent manner. This review is focused on our current understanding of the extracellular distribution of multiple growth factors controlled by HSPGs in mammalian development.

scholarly journals Identification of two neutralization epitopes on the capsid protein of avian hepatitis E virus

2008 ◽  
Vol 89 (2) ◽  
pp. 500-508 ◽  
Author(s):  
E.-M. Zhou ◽  
H. Guo ◽  
F. F. Huang ◽  
Z. F. Sun ◽  
X. J. Meng
Keyword(s):  
Capsid Protein ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Avian Hepatitis E Virus

Production and characterization of a fusion form of hepatitis E virus tORF2 capsid protein in Escherichia coli

2020 ◽  
pp. 1-8
Author(s):  
Mohamed Boumaiza ◽  
Khaled Trabelsi ◽  
Zeineb Choucha ◽  
Ines Akrouti ◽  
Serena Leone ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Capsid Protein ◽  
Hepatitis E Virus ◽  
Hepatitis E

scholarly journals Distinct glycosaminoglycan chain length and sulfation patterns required for cellular uptake of Tau, Aβ, and α-Synuclein

2017 ◽  
Author(s):  
Barbara E. Stopschinski ◽  
Brandon B. Holmes ◽  
Gregory M. Miller ◽  
Jaime Vaquer-Alicea ◽  
Linda C. Hsieh-Wilson ◽  
...  
Keyword(s):  
Cell Surface ◽  
Neurodegenerative Diseases ◽  
Heparan Sulfate ◽  
Chain Length ◽  
Cellular Uptake ◽  
Genetic Manipulation ◽  
Heparan Sulfate Proteoglycans ◽  
Cell Uptake ◽  
Major Genes

AbstractTranscellular propagation of aggregate “seeds” has been proposed to mediate progression of neurodegenerative diseases in tauopathies and α-synucleinopathies. We have previously determined that tau and α-synuclein aggregates bind heparan sulfate proteoglycans (HSPGs) on the cell surface. This mediates uptake and intracellular seeding. The specificity and mode of binding to HSPGs has been unknown. We used modified heparins to determine the size and sulfation requirements of glycosaminoglycan (GAGs) binding to aggregates in biochemical and cell uptake and seeding assays. Aggregates of tau require a precise GAG architecture with defined sulfate moieties in the N- and 6-O-positions, whereas α-synuclein and Aβ rely slightly more on overall charge on the GAGs. To determine the genetic requirements for aggregate uptake, we individually knocked out the major genes of the HSPG synthesis pathway using CRISPR/Cas9 in HEK293T cells. Knockout of EXT1, EXT2 and EXTL3, N-sulfotransferase (NDST1), and 6-O-sulfotransferase (HS6ST2) significantly reduced tau uptake. α-Synuclein was not sensitive to HS6ST2 knockout. Good correlation between pharmacologic and genetic manipulation of GAG binding by tau and α-synuclein indicates specificity that may help elucidate a path to mechanism-based inhibition of transcellular propagation of pathology.

scholarly journals Hepatitis E virus genotype 3 and capsid protein in the blood and urine of immunocompromised patients

2019 ◽  
Vol 78 (3) ◽  
pp. 232-240 ◽  
Author(s):  
Olivier Marion ◽  
Nicolas Capelli ◽  
Sebastien Lhomme ◽  
Martine Dubois ◽  
Mélanie Pucelle ◽  
...  
Keyword(s):  
Capsid Protein ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Immunocompromised Patients ◽  
Genotype 3 ◽  
Virus Genotype
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