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HAMAP rule MF_04076

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General rule information [?]

Accession MF_04076
Dates 15-MAY-2017 (Created)
15-DEC-2023 (Last updated, Version 9)
Scope(s) Viruses
Template(s) P0C767 (HBEAG_HBVCJ); Q76R61 (CAPSD_HBVCJ); [ Recover all ]
Triggered by HAMAP; MF_04076 (Get profile general information and statistics)

Propagated annotation [?]

Identifier, protein and gene names [?]

case <FTTag:HBEAG>
Identifier HBEAG
Protein name RecName: Full=External core antigen;
AltName: Full=HBeAg;
AltName: Full=Precore protein;
AltName: Full=p25;
                 Flags: Precursor;
Gene name Name=C;
Identifier CAPSD
Protein name RecName: Full=Capsid protein;
AltName: Full=Core antigen;
AltName: Full=Core protein;
AltName: Full=HBcAg;
AltName: Full=p21.5;
Gene name Name=C;
end case

Comments [?]

case <FTTag:HBEAG>
FUNCTIONMay regulate immune response to the intracellular capsid in acting as a T-cell tolerogen, by having an immunoregulatory effect which prevents destruction of infected cells by cytotoxic T-cells. This immune regulation may predispose to chronicity during perinatal infections and prevent severe liver injury during adult infections.
SUBCELLULAR LOCATIONSecreted. Host nucleus.
PTMCleaved by host furin.
SIMILARITYBelongs to the orthohepadnavirus precore antigen family.
FUNCTIONSelf assembles to form an icosahedral capsid. Most capsids appear to be large particles with an icosahedral symmetry of T=4 and consist of 240 copies of capsid protein, though a fraction forms smaller T=3 particles consisting of 180 capsid proteins. Entering capsids are transported along microtubules to the nucleus. Phosphorylation of the capsid is thought to induce exposure of nuclear localization signal in the C-terminal portion of the capsid protein that allows binding to the nuclear pore complex via the importin (karyopherin-) alpha and beta. Capsids are imported in intact form through the nuclear pore into the nuclear basket, where it probably binds NUP153. Only capsids that contain the mature viral genome can release the viral DNA and capsid protein into the nucleoplasm. Immature capsids get stuck in the basket. Capsids encapsulate the pre-genomic RNA and the P protein. Pre-genomic RNA is reverse-transcribed into DNA while the capsid is still in the cytoplasm. The capsid can then either be directed to the nucleus, providing more genomes for transcription, or bud through the endoplasmic reticulum to provide new virions.
SUBUNITHomodimerizes, then multimerizes. Interacts with cytosol exposed regions of viral L glycoprotein present in the reticulum-to- Golgi compartment. Interacts with human FLNB. Phosphorylated form interacts with host importin alpha; this interaction depends on the exposure of the NLS, which itself depends upon genome maturation and/or phosphorylation of the capsid protein. Interacts with host NUP153.
SUBCELLULAR LOCATIONVirion. Host cytoplasm.
PTMPhosphorylated by host SRPK1, SRPK2, and maybe protein kinase C or GAPDH. Phosphorylation is critical for pregenomic RNA packaging. Protein kinase C phosphorylation is stimulated by HBx protein and may play a role in transport of the viral genome to the nucleus at the late step during the viral replication cycle.
SIMILARITYBelongs to the orthohepadnavirus core antigen family.
end case

Keywords [?]

Gene Ontology [?]

case <FTTag:HBEAG>
GO:0005576; Cellular component:extracellular region
GO:0042025; Cellular component:host cell nucleus
GO:0019049; Biological process:virus-mediated perturbation of host defense response
else; https://www.ebi.ac.uk/QuickGO/term/else
GO:0030430; Cellular component:host cell cytoplasm
GO:0039619; Cellular component:T=4 icosahedral viral capsid
GO:0003677; Molecular function:DNA binding
GO:0003723; Molecular function:RNA binding
GO:0075521; Biological process:microtubule-dependent intracellular transport of viral material towards nucleus
GO:0046718; Biological process:viral entry into host cell
GO:0075732; Biological process:viral penetration into host nucleus
end case
GO:0005198; Molecular function:structural molecule activity

Cross-references [?]

Pfam PF08290; Hep_core_N; 0-1;
Pfam PF00906; Hepatitis_core; 2-3;
General Signal; -; 1;

Features [?]

From: HBEAG_HBVCJ (P0C767)
Key From To Description Tag Condition FTGroup
REGION 25 27 /note="HBEAG" HBEAG G-W-L
case <FTTag:HBEAG>
SITE 183 184 /note="Cleavage; by host" R-S
DISULFID 77 77 /note="Interchain" C
DISULFID 90 90 /note="Interchain" C
From: CAPSD_HBVCJ (Q76R61)
Key From To Description Tag Condition FTGroup
REGION 177 183 /note="RNA binding"
MOTIF 158 175 /note="Bipartite nuclear localization signal"
MOD_RES 155 155 /note="Phosphoserine; by host" S
MOD_RES 162 162 /note="Phosphoserine; by host" S
MOD_RES 170 170 /note="Phosphoserine; by host" S
end case

Additional information [?]

Size range 182-218 amino acids
Related rules None
Fusion Nter: None Cter: None

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