POLG_HCVE1
ID POLG_HCVE1 Reviewed; 192 AA.
AC P27954;
DT 01-AUG-1992, integrated into UniProtKB/Swiss-Prot.
DT 01-AUG-1992, sequence version 1.
DT 03-AUG-2022, entry version 106.
DE RecName: Full=Genome polyprotein;
DE Contains:
DE RecName: Full=Core protein precursor;
DE AltName: Full=Capsid protein C;
DE AltName: Full=p23;
DE Contains:
DE RecName: Full=Mature core protein;
DE AltName: Full=p21;
DE Contains:
DE RecName: Full=Envelope glycoprotein E1;
DE AltName: Full=gp32;
DE AltName: Full=gp35;
DE Flags: Fragment;
OS Hepatitis C virus (isolate EC1) (HCV).
OC Viruses; Riboviria; Orthornavirae; Kitrinoviricota; Flasuviricetes;
OC Amarillovirales; Flaviviridae; Hepacivirus.
OX NCBI_TaxID=11107;
OH NCBI_TaxID=9606; Homo sapiens (Human).
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RX PubMed=1846505; DOI=10.1016/0042-6822(91)90104-j;
RA Weiner A.J., Brauer M.J., Rosenblatt J., Richman K.H., Tung J.,
RA Crawford K., Bonino F., Saracco G., Choo Q.-L., Houghton M., Han J.H.;
RT "Variable and hypervariable domains are found in the regions of HCV
RT corresponding to the flavivirus envelope and NS1 proteins and the
RT pestivirus envelope glycoproteins.";
RL Virology 180:842-848(1991).
RN [2]
RP REVIEW.
RX PubMed=10718937; DOI=10.1046/j.1365-2893.2000.00201.x;
RA McLauchlan J.;
RT "Properties of the hepatitis C virus core protein: a structural protein
RT that modulates cellular processes.";
RL J. Viral Hepat. 7:2-14(2000).
RN [3]
RP REVIEW.
RX PubMed=14752815; DOI=10.1002/hep.20032;
RA Penin F., Dubuisson J., Rey F.A., Moradpour D., Pawlotsky J.-M.;
RT "Structural biology of hepatitis C virus.";
RL Hepatology 39:5-19(2004).
CC -!- FUNCTION: [Mature core protein]: Packages viral RNA to form a viral
CC nucleocapsid, and promotes virion budding (Probable). Participates in
CC the viral particle production as a result of its interaction with the
CC non-structural protein 5A (By similarity). Binds RNA and may function
CC as a RNA chaperone to induce the RNA structural rearrangements taking
CC place during virus replication (By similarity). Modulates viral
CC translation initiation by interacting with viral IRES and 40S ribosomal
CC subunit (By similarity). Affects various cell signaling pathways, host
CC immunity and lipid metabolism (Probable). Prevents the establishment of
CC cellular antiviral state by blocking the interferon-alpha/beta (IFN-
CC alpha/beta) and IFN-gamma signaling pathways and by blocking the
CC formation of phosphorylated STAT1 and promoting ubiquitin-mediated
CC proteasome-dependent degradation of STAT1 (By similarity). Activates
CC STAT3 leading to cellular transformation (By similarity). Regulates the
CC activity of cellular genes, including c-myc and c-fos (By similarity).
CC May repress the promoter of p53, and sequester CREB3 and SP110 isoform
CC 3/Sp110b in the cytoplasm (By similarity). Represses cell cycle
CC negative regulating factor CDKN1A, thereby interrupting an important
CC check point of normal cell cycle regulation (By similarity). Targets
CC transcription factors involved in the regulation of inflammatory
CC responses and in the immune response: suppresses TNF-induced NF-kappa-B
CC activation, and activates AP-1 (By similarity). Binds to dendritic
CC cells (DCs) via C1QR1, resulting in down-regulation of T-lymphocytes
CC proliferation (By similarity). Alters lipid metabolism by interacting
CC with hepatocellular proteins involved in lipid accumulation and storage
CC (By similarity). Induces up-regulation of FAS promoter activity, and
CC thereby contributes to the increased triglyceride accumulation in
CC hepatocytes (steatosis) (By similarity). {ECO:0000250|UniProtKB:P26662,
CC ECO:0000250|UniProtKB:P26664, ECO:0000250|UniProtKB:P27958,
CC ECO:0000250|UniProtKB:P29846, ECO:0000250|UniProtKB:Q99IB8,
CC ECO:0000305}.
CC -!- FUNCTION: [Envelope glycoprotein E1]: Forms a heterodimer with envelope
CC glycoprotein E2, which mediates virus attachment to the host cell,
CC virion internalization through clathrin-dependent endocytosis and
CC fusion with host membrane (By similarity). Fusion with the host cell is
CC most likely mediated by both E1 and E2, through conformational
CC rearrangements of the heterodimer required for fusion rather than a
CC classical class II fusion mechanism (By similarity). E1/E2 heterodimer
CC binds host apolipoproteins such as APOB and ApoE thereby forming a
CC lipo-viro-particle (LVP) (By similarity). APOE associated to the LVP
CC allows the initial virus attachment to cell surface receptors such as
CC the heparan sulfate proteoglycans (HSPGs), syndecan-1 (SDC1), syndecan-
CC 1 (SDC2), the low-density lipoprotein receptor (LDLR) and scavenger
CC receptor class B type I (SCARB1) (By similarity). The cholesterol
CC transfer activity of SCARB1 allows E2 exposure and binding of E2 to
CC SCARB1 and the tetraspanin CD81 (By similarity). E1/E2 heterodimer
CC binding on CD81 activates the epithelial growth factor receptor (EGFR)
CC signaling pathway (By similarity). Diffusion of the complex E1-E2-EGFR-
CC SCARB1-CD81 to the cell lateral membrane allows further interaction
CC with Claudin 1 (CLDN1) and occludin (OCLN) to finally trigger HCV entry
CC (By similarity). {ECO:0000250|UniProtKB:P27958}.
CC -!- SUBUNIT: [Mature core protein]: Homooligomer (By similarity). Interacts
CC with E1 (via C-terminus) (By similarity). Interacts with the non-
CC structural protein 5A (By similarity). Interacts (via N-terminus) with
CC host STAT1 (via SH2 domain); this interaction results in decreased
CC STAT1 phosphorylation and ubiquitin-mediated proteasome-dependent STAT1
CC degradation, leading to decreased IFN-stimulated gene transcription (By
CC similarity). Interacts with host STAT3; this interaction constitutively
CC activates STAT3 (By similarity). Interacts with host LTBR receptor (By
CC similarity). Interacts with host TNFRSF1A receptor and possibly induces
CC apoptosis (By similarity). Interacts with host HNRPK (By similarity).
CC Interacts with host YWHAE (By similarity). Interacts with host
CC UBE3A/E6AP (By similarity). Interacts with host DDX3X (By similarity).
CC Interacts with host APOA2 (By similarity). Interacts with host RXRA
CC protein (By similarity). Interacts with host SP110 isoform 3/Sp110b;
CC this interaction sequesters the transcriptional corepressor SP110 away
CC from the nucleus (By similarity). Interacts with host CREB3 nuclear
CC transcription protein; this interaction triggers cell transformation
CC (By similarity). Interacts with host ACY3 (By similarity). Interacts
CC with host C1QR1 (By similarity). Interacts with host RBM24; this
CC interaction, which enhances the interaction of the mature core protein
CC with 5'-UTR, may inhibit viral translation and favor replication (By
CC similarity). Interacts with host EIF2AK2/PKR; this interaction induces
CC the autophosphorylation of EIF2AK2 (By similarity). Part of the viral
CC assembly initiation complex composed of NS2, E1, E2, NS3, NS4A, NS5A
CC and the mature core protein (By similarity).
CC {ECO:0000250|UniProtKB:P26662, ECO:0000250|UniProtKB:P26664,
CC ECO:0000250|UniProtKB:P27958, ECO:0000250|UniProtKB:P29846,
CC ECO:0000250|UniProtKB:Q03463, ECO:0000250|UniProtKB:Q5EG65,
CC ECO:0000250|UniProtKB:Q99IB8}.
CC -!- SUBUNIT: [Envelope glycoprotein E1]: Forms a heterodimer with envelope
CC glycoprotein E2 (By similarity). Interacts with mature core protein (By
CC similarity). Interacts with protease NS2 (By similarity). The
CC heterodimer E1/E2 interacts with host CLDN1; this interaction plays a
CC role in viral entry into host cell (By similarity). Interacts with host
CC SPSB2 (via C-terminus) (By similarity). Part of the viral assembly
CC initiation complex composed of NS2, E1, E2, NS3, NS4A, NS5A and the
CC mature core protein (By similarity). {ECO:0000250|UniProtKB:P27958,
CC ECO:0000250|UniProtKB:Q99IB8}.
CC -!- SUBCELLULAR LOCATION: [Core protein precursor]: Host endoplasmic
CC reticulum membrane {ECO:0000250|UniProtKB:P26664}; Single-pass membrane
CC protein {ECO:0000255}. Host mitochondrion membrane
CC {ECO:0000250|UniProtKB:P26664}; Single-pass type I membrane protein
CC {ECO:0000255}. Note=The C-terminal transmembrane domain of the core
CC protein precursor contains an ER signal leading the nascent polyprotein
CC to the ER membrane.
CC -!- SUBCELLULAR LOCATION: [Mature core protein]: Virion
CC {ECO:0000250|UniProtKB:Q99IB8}. Host cytoplasm
CC {ECO:0000250|UniProtKB:Q99IB8}. Host nucleus
CC {ECO:0000250|UniProtKB:Q01403}. Host lipid droplet
CC {ECO:0000250|UniProtKB:Q99IB8}. Note=Only a minor proportion of core
CC protein is present in the nucleus (By similarity). Probably present on
CC the surface of lipid droplets (By similarity).
CC {ECO:0000250|UniProtKB:P27958}.
CC -!- SUBCELLULAR LOCATION: [Envelope glycoprotein E1]: Virion membrane
CC {ECO:0000305}; Single-pass type I membrane protein {ECO:0000305}. Host
CC endoplasmic reticulum membrane; Single-pass type I membrane protein
CC {ECO:0000250|UniProtKB:P27958}. Note=The C-terminal transmembrane
CC domain acts as a signal sequence and forms a hairpin structure before
CC cleavage by host signal peptidase (By similarity). After cleavage, the
CC membrane sequence is retained at the C-terminus of the protein, serving
CC as ER membrane anchor (By similarity). A reorientation of the second
CC hydrophobic stretch occurs after cleavage producing a single reoriented
CC transmembrane domain (By similarity). These events explain the final
CC topology of the protein (By similarity).
CC {ECO:0000250|UniProtKB:P27958}.
CC -!- DOMAIN: [Envelope glycoprotein E1]: The transmembrane regions of
CC envelope E1 and E2 glycoproteins are involved in heterodimer formation,
CC ER localization, and assembly of these proteins.
CC {ECO:0000250|UniProtKB:P27958}.
CC -!- PTM: [Genome polyprotein]: Specific enzymatic cleavages in vivo yield
CC mature proteins (By similarity). The structural proteins, core, E1, E2
CC and p7 are produced by proteolytic processing by host signal peptidases
CC (By similarity). The core protein precursor is synthesized as a 23 kDa,
CC which is retained in the ER membrane through the hydrophobic signal
CC peptide (By similarity). Cleavage by the signal peptidase releases the
CC 21 kDa mature core protein (By similarity). The cleavage of the core
CC protein precursor occurs between aminoacids 176 and 188 but the exact
CC cleavage site is not known (By similarity). Some degraded forms of the
CC core protein appear as well during the course of infection (By
CC similarity). The other proteins (p7, NS2, NS3, NS4A, NS4B, NS5A and
CC NS5B) are cleaved by the viral proteases (By similarity).
CC Autoprocessing between NS2 and NS3 is mediated by the NS2 cysteine
CC protease catalytic domain and regulated by the NS3 N-terminal domain
CC (By similarity). {ECO:0000250|UniProtKB:P26664,
CC ECO:0000250|UniProtKB:P27958}.
CC -!- PTM: [Mature core protein]: Phosphorylated by host PKC and PKA.
CC {ECO:0000250|UniProtKB:Q01403}.
CC -!- PTM: [Mature core protein]: Ubiquitinated; mediated by UBE3A and
CC leading to core protein subsequent proteasomal degradation.
CC {ECO:0000250|UniProtKB:Q03463}.
CC -!- PTM: [Envelope glycoprotein E1]: Highly N-glycosylated.
CC {ECO:0000250|UniProtKB:P27958}.
CC -!- MISCELLANEOUS: Viral particle assembly takes place at the surface of
CC ER-derived membranes in close proximity to lipid droplets. NS2
CC associates with E1/E2 glycoproteins, NS3 and NS5A, which interacts with
CC the viral RNA and core protein to promote genome encapsidation. The
CC nucleocapsid buds at the ER membrane where E1/E2 glycoproteins are
CC anchored and afterward associate with nascent lipid droplet to acquire
CC APOE and APOC. Secretion of viral particles is probably regulated by
CC viroporin p7. {ECO:0000305}.
CC -!- MISCELLANEOUS: [Mature core protein]: Exerts viral interference on
CC hepatitis B virus when HCV and HBV coinfect the same cell, by
CC suppressing HBV gene expression, RNA encapsidation and budding.
CC {ECO:0000250|UniProtKB:P26662}.
CC -!- SIMILARITY: Belongs to the hepacivirus polyprotein family.
CC {ECO:0000305}.
CC -!- CAUTION: The core gene probably also codes for alternative reading
CC frame proteins (ARFPs). Many functions depicted for the core protein
CC might belong to the ARFPs. {ECO:0000305}.
CC -!- WEB RESOURCE: Name=Virus Pathogen Resource;
CC URL="https://www.viprbrc.org/brc/home.spg?decorator=flavi_hcv";
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DR EMBL; X53135; CAA37295.1; -; Genomic_RNA.
DR SMR; P27954; -.
DR euHCVdb; X53135; -.
DR GO; GO:0044167; C:host cell endoplasmic reticulum membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0044186; C:host cell lipid droplet; IEA:UniProtKB-SubCell.
DR GO; GO:0044191; C:host cell mitochondrial membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0042025; C:host cell nucleus; IEA:UniProtKB-SubCell.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0019031; C:viral envelope; IEA:UniProtKB-KW.
DR GO; GO:0019013; C:viral nucleocapsid; IEA:UniProtKB-KW.
DR GO; GO:0055036; C:virion membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR GO; GO:0005198; F:structural molecule activity; IEA:InterPro.
DR GO; GO:0075512; P:clathrin-dependent endocytosis of virus by host cell; IEA:UniProtKB-KW.
DR GO; GO:0039654; P:fusion of virus membrane with host endosome membrane; IEA:UniProtKB-KW.
DR GO; GO:0019062; P:virion attachment to host cell; IEA:UniProtKB-KW.
DR InterPro; IPR002521; HCV_Core_C.
DR InterPro; IPR002519; HCV_Env.
DR Pfam; PF01542; HCV_core; 1.
DR Pfam; PF01539; HCV_env; 1.
PE 3: Inferred from homology;
KW Apoptosis; Capsid protein; Clathrin-mediated endocytosis of virus by host;
KW Fusion of virus membrane with host endosomal membrane;
KW Fusion of virus membrane with host membrane; Glycoprotein; Host cytoplasm;
KW Host endoplasmic reticulum; Host lipid droplet; Host membrane;
KW Host mitochondrion; Host nucleus; Host-virus interaction;
KW Interferon antiviral system evasion; Membrane; Oncogene; Ribonucleoprotein;
KW RNA-binding; Transmembrane; Transmembrane helix; Ubl conjugation;
KW Viral attachment to host cell; Viral envelope protein; Viral nucleoprotein;
KW Viral penetration into host cytoplasm; Virion; Virus endocytosis by host;
KW Virus entry into host cell.
FT CHAIN <1..>192
FT /note="Genome polyprotein"
FT /id="PRO_0000450899"
FT CHAIN <1..75
FT /note="Core protein precursor"
FT /id="PRO_0000037555"
FT CHAIN <1..61
FT /note="Mature core protein"
FT /id="PRO_0000037556"
FT PROPEP 62..75
FT /note="ER anchor for the core protein, removed in mature
FT form by host signal peptidase"
FT /id="PRO_0000037557"
FT CHAIN 76..>192
FT /note="Envelope glycoprotein E1"
FT /id="PRO_0000037558"
FT TOPO_DOM <1..52
FT /note="Cytoplasmic"
FT /evidence="ECO:0000250|UniProtKB:P27958"
FT TRANSMEM 53..73
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P27958"
FT TOPO_DOM 74..>192
FT /note="Lumenal"
FT /evidence="ECO:0000250|UniProtKB:P27958"
FT REGION 6..57
FT /note="Interaction with APOA2"
FT /evidence="ECO:0000250|UniProtKB:P29846"
FT REGION 48..51
FT /note="Important for lipid droplets localization"
FT /evidence="ECO:0000250|UniProtKB:P27958"
FT REGION 149..180
FT /note="Important for fusion"
FT /evidence="ECO:0000250|UniProtKB:P27958"
FT SITE 61..62
FT /note="Cleavage; by host signal peptide peptidase"
FT /evidence="ECO:0000250|UniProtKB:P26662"
FT SITE 75..76
FT /note="Cleavage; by host signal peptidase"
FT /evidence="ECO:0000250|UniProtKB:P26662"
FT CARBOHYD 80
FT /note="N-linked (GlcNAc...) asparagine; by host"
FT /evidence="ECO:0000250|UniProtKB:P27958"
FT CARBOHYD 93
FT /note="N-linked (GlcNAc...) asparagine; by host"
FT /evidence="ECO:0000250|UniProtKB:P27958"
FT CARBOHYD 118
FT /note="N-linked (GlcNAc...) asparagine; by host"
FT /evidence="ECO:0000250|UniProtKB:P27958"
FT CARBOHYD 189
FT /note="N-linked (GlcNAc...) asparagine; by host"
FT /evidence="ECO:0000255"
FT NON_TER 1
FT NON_TER 192
SQ SEQUENCE 192 AA; 20315 MW; 98E488F4C335A84C CRC64;
RNLGKVIDTL TCGFADLMGY IPLVGAPLGG AARALAHGVR VLEDGVNYAT GNLPGCSFSI
FLLALLSCLT VPASAYQVRN SSGLYHVTND CPNSSIVYEA ADAILHTPGC VPCVHEGNVS
RCWVAMTPTV ATRDGKLPTT QLRRHIDLLV GSATLCSALY VGDLCGSVFL VGQLFTFSPR
RHWTTQGCNC SI
