| IED ID | IndEnz0002007790 |
| Enzyme Type ID | protease007790 |
| Protein Name |
Genome polyprotein Cleaved into: Envelope glycoprotein E1 gp32 gp35 ; Envelope glycoprotein E2 NS1 gp68 gp70 Fragment |
| Gene Name | |
| Organism | Hepatitis C virus (isolate EC10) (HCV) |
| Taxonomic Lineage | Viruses Riboviria Orthornavirae Kitrinoviricota Flasuviricetes Amarillovirales Flaviviridae Hepacivirus Hepacivirus C unclassified Hepatitis C virus Hepatitis C virus (isolate EC10) (HCV) |
| Enzyme Sequence | TTQGCNCSIYPGHITGHRMAWDMMMNWSPTTALVVAQLLRIPQAILDMIAGAHWGVLAGIAYFSMVGNWAKVLAVLLLFAGVDAETHVTGGIAAKTTASLTGLFNLGAKQNIQLINTNGSWHINRTALNCNDSLNTGW |
| Enzyme Length | 138 |
| Uniprot Accession Number | P27953 |
| Absorption | |
| Active Site | |
| Activity Regulation | |
| Binding Site | |
| Calcium Binding | |
| catalytic Activity | |
| DNA Binding | |
| EC Number | |
| Enzyme Function | FUNCTION: [Envelope glycoprotein E1]: Forms a heterodimer with envelope glycoprotein E2, which mediates virus attachment to the host cell, virion internalization through clathrin-dependent endocytosis and fusion with host membrane (By similarity). Fusion with the host cell is most likely mediated by both E1 and E2, through conformational rearrangements of the heterodimer required for fusion rather than a classical class II fusion mechanism (By similarity). E1/E2 heterodimer binds host apolipoproteins such as APOB and ApoE thereby forming a lipo-viro-particle (LVP) (By similarity). APOE associated to the LVP allows the initial virus attachment to cell surface receptors such as the heparan sulfate proteoglycans (HSPGs), syndecan-1 (SDC1), syndecan-1 (SDC2), the low-density lipoprotein receptor (LDLR) and scavenger receptor class B type I (SCARB1) (By similarity). The cholesterol transfer activity of SCARB1 allows E2 exposure and binding of E2 to SCARB1 and the tetraspanin CD81 (By similarity). E1/E2 heterodimer binding on CD81 activates the epithelial growth factor receptor (EGFR) signaling pathway (By similarity). Diffusion of the complex E1-E2-EGFR-SCARB1-CD81 to the cell lateral membrane allows further interaction with Claudin 1 (CLDN1) and occludin (OCLN) to finally trigger HCV entry (By similarity). {ECO:0000250|UniProtKB:P27958}.; FUNCTION: [Envelope glycoprotein E2]: Forms a heterodimer with envelope glycoprotein E1, which mediates virus attachment to the host cell, virion internalization through clathrin-dependent endocytosis and fusion with host membrane (By similarity). Fusion with the host cell is most likely mediated by both E1 and E2, through conformational rearrangements of the heterodimer required for fusion rather than a classical class II fusion mechanism (By similarity). The interaction between envelope glycoprotein E2 and host apolipoprotein E/APOE allows the proper assembly, maturation and infectivity of the viral particles (By similarity). This interaction is probably promoted via the up-regulation of cellular autophagy by the virus (By similarity). E1/E2 heterodimer binds host apolipoproteins such as APOB and APOE thereby forming a lipo-viro-particle (LVP) (By similarity). APOE associated to the LVP allows the initial virus attachment to cell surface receptors such as the heparan sulfate proteoglycans (HSPGs), syndecan-1 (SDC1), syndecan-1 (SDC2), the low-density lipoprotein receptor (LDLR) and scavenger receptor class B type I (SCARB1) (By similarity). The cholesterol transfer activity of SCARB1 allows E2 exposure and binding of E2 to SCARB1 and the tetraspanin CD81 (By similarity). E1/E2 heterodimer binding on CD81 activates the epithelial growth factor receptor (EGFR) signaling pathway (By similarity). Diffusion of the complex E1-E2-EGFR-SCARB1-CD81 to the cell lateral membrane allows further interaction with Claudin 1 (CLDN1) and occludin (OCLN) to finally trigger HCV entry (By similarity). Inhibits host EIF2AK2/PKR activation, preventing the establishment of an antiviral state (By similarity). Viral ligand for CD209/DC-SIGN and CLEC4M/DC-SIGNR, which are respectively found on dendritic cells (DCs), and on liver sinusoidal endothelial cells and macrophage-like cells of lymph node sinuses (By similarity). These interactions allow the capture of circulating HCV particles by these cells and subsequent facilitated transmission to permissive cells such as hepatocytes and lymphocyte subpopulations (By similarity). {ECO:0000250|UniProtKB:P26664, ECO:0000250|UniProtKB:P27958}. |
| Temperature Dependency | |
| PH Dependency | |
| Pathway | |
| nucleotide Binding | |
| Features | Chain (3); Glycosylation (4); Non-terminal residue (2); Region (1); Site (1); Topological domain (2); Transmembrane (1) |
| Keywords | Clathrin-mediated endocytosis of virus by host;Fusion of virus membrane with host endosomal membrane;Fusion of virus membrane with host membrane;Glycoprotein;Host endoplasmic reticulum;Host lipid droplet;Host membrane;Host-virus interaction;Membrane;Transmembrane;Transmembrane helix;Viral attachment to host cell;Viral envelope protein;Viral penetration into host cytoplasm;Virion;Virus endocytosis by host;Virus entry into host cell |
| Interact With | |
| Induction | |
| Subcellular Location | SUBCELLULAR LOCATION: [Envelope glycoprotein E1]: Virion membrane {ECO:0000305}; Single-pass type I membrane protein {ECO:0000305}. Host endoplasmic reticulum membrane; Single-pass type I membrane protein {ECO:0000250|UniProtKB:P27958}. Note=The C-terminal transmembrane domain acts as a signal sequence and forms a hairpin structure before cleavage by host signal peptidase (By similarity). After cleavage, the membrane sequence is retained at the C-terminus of the protein, serving as ER membrane anchor (By similarity). A reorientation of the second hydrophobic stretch occurs after cleavage producing a single reoriented transmembrane domain (By similarity). These events explain the final topology of the protein (By similarity). {ECO:0000250|UniProtKB:P27958}.; SUBCELLULAR LOCATION: [Envelope glycoprotein E2]: Virion membrane {ECO:0000305}; Single-pass type I membrane protein {ECO:0000305}. Host endoplasmic reticulum membrane; Single-pass type I membrane protein {ECO:0000250|UniProtKB:P27958}. Host lipid droplet {ECO:0000250|UniProtKB:Q9WMX2}. Note=The C-terminal transmembrane domain acts as a signal sequence and forms a hairpin structure before cleavage by host signal peptidase (By similarity). After cleavage, the membrane sequence is retained at the C-terminus of the protein, serving as ER membrane anchor (By similarity). A reorientation of the second hydrophobic stretch occurs after cleavage producing a single reoriented transmembrane domain (By similarity). These events explain the final topology of the protein (By similarity). {ECO:0000250|UniProtKB:P27958}. |
| Modified Residue | |
| Post Translational Modification | PTM: [Genome polyprotein]: Specific enzymatic cleavages in vivo yield mature proteins (By similarity). The structural proteins, core, E1, E2 and p7 are produced by proteolytic processing by host signal peptidases (By similarity). The core protein precursor is synthesized as a 23 kDa, which is retained in the ER membrane through the hydrophobic signal peptide (By similarity). Cleavage by the signal peptidase releases the 21 kDa mature core protein (By similarity). The cleavage of the core protein precursor occurs between aminoacids 176 and 188 but the exact cleavage site is not known (By similarity). Some degraded forms of the core protein appear as well during the course of infection (By similarity). The other proteins (p7, NS2, NS3, NS4A, NS4B, NS5A and NS5B) are cleaved by the viral proteases (By similarity). Autoprocessing between NS2 and NS3 is mediated by the NS2 cysteine protease catalytic domain and regulated by the NS3 N-terminal domain (By similarity). {ECO:0000250|UniProtKB:P26664, ECO:0000250|UniProtKB:P27958}.; PTM: [Envelope glycoprotein E1]: Highly N-glycosylated. {ECO:0000250|UniProtKB:P27958}.; PTM: [Envelope glycoprotein E2]: Highly N-glycosylated. {ECO:0000250|UniProtKB:P27958}. |
| Signal Peptide | |
| Structure 3D | |
| Cross Reference PDB | - |
| Mapped Pubmed ID | - |
| Motif | |
| Gene Encoded By | |
| Mass | 14,781 |
| Kinetics | |
| Metal Binding | |
| Rhea ID | |
| Cross Reference Brenda |