O11883 · O11883_HBV
- ProteinProtein X
- GeneX
- StatusUniProtKB unreviewed (TrEMBL)
- Organism
- Amino acids154 (go to sequence)
- Protein existenceInferred from homology
- Annotation score3/5
Function
function
Multifunctional protein that may modulate protein degradation pathways, apoptosis, transcription, signal transduction, cell cycle progress, and genetic stability by directly or indirectly interacting with host factors.
Multifunctional protein that plays a role in silencing host antiviral defenses and promoting viral transcription. Does not seem to be essential for HBV infection. May be directly involved in development of cirrhosis and liver cancer (hepatocellular carcinoma). Most of cytosolic activities involve modulation of cytosolic calcium. The effect on apoptosis is controversial depending on the cell types in which the studies have been conducted. May induce apoptosis by localizing in mitochondria and causing loss of mitochondrial membrane potential. May also modulate apoptosis by binding host CFLAR, a key regulator of the death-inducing signaling complex (DISC). Promotes viral transcription by using the host E3 ubiquitin ligase DDB1 to target the SMC5-SMC6 complex to proteasomal degradation. This host complex would otherwise bind to viral episomal DNA, and prevents its transcription. Moderately stimulates transcription of many different viral and cellular transcription elements. Promoters and enhancers stimulated by HBx contain DNA binding sites for NF-kappa-B, AP-1, AP-2, c-EBP, ATF/CREB, or the calcium-activated factor NF-AT.
GO annotations
all annotations | all molecular function | virus receptor activity | dna binding | rna binding | cytoskeletal motor activity | catalytic activity | gtpase activity | structural molecule activity | transporter activity | cytoskeletal protein binding | lipid binding | cyclase activity | antioxidant activity | oxidoreductase activity | transferase activity | hydrolase activity | lyase activity | isomerase activity | ligase activity | protein tag activity | cargo receptor activity | histone binding | protein folding chaperone | translation regulator activity | nutrient reservoir activity | receptor ligand activity | molecular transducer activity | molecular adaptor activity | toxin activity | cell adhesion mediator activity | molecular function regulator activity | virus coreceptor activity | catalytic activity, acting on a protein | catalytic activity, acting on dna | catalytic activity, acting on rna | molecular carrier activity | transcription regulator activity | general transcription initiation factor activity | molecular sensor activity | molecular sequestering activity | atp-dependent activity | other molecular function | all biological process | mitotic cell cycle | cytokinesis | cytoplasmic translation | immune system process | muscle system process | circulatory system process | renal system process | respiratory system process | carbohydrate metabolic process | generation of precursor metabolites and energy | dna replication | dna repair | dna recombination | chromatin organization | dna-templated transcription | regulation of dna-templated transcription | trna metabolic process | protein folding | protein glycosylation | amino acid metabolic process | modified amino acid metabolic process | lipid metabolic process | vitamin metabolic process | sulfur compound metabolic process | intracellular protein transport | nucleocytoplasmic transport | autophagy | inflammatory response | mitochondrion organization | cytoskeleton organization | microtubule-based movement | peroxisome organization | lysosome organization | chromosome segregation | cell adhesion | establishment or maintenance of cell polarity | programmed cell death | photosynthesis | mrna metabolic process | snrna metabolic process | vesicle-mediated transport | reproductive process | digestive system process | signaling | cell differentiation | protein catabolic process | extracellular matrix organization | regulatory ncrna-mediated gene silencing | telomere organization | cell junction organization | wound healing | ribosome biogenesis | cilium organization | anatomical structure development | cell motility | nervous system process | endocrine process | protein maturation | transmembrane transport | nucleobase-containing small molecule metabolic process | hepaticobiliary system process | membrane organization | protein-containing complex assembly | cell wall organization or biogenesis | nitrogen cycle metabolic process | protein localization to plasma membrane | defense response to other organism | detoxification | meiotic nuclear division | mitotic nuclear division | mitochondrial gene expression | carbohydrate derivative metabolic process | other biological process | all cellular component | nuclear chromosome | extracellular region | extracellular space | cell wall | nucleus | nuclear envelope | nucleoplasm | chromosome | nucleolus | mitochondrion | lysosome | endosome | vacuole | peroxisome | endoplasmic reticulum | golgi apparatus | lipid droplet | microtubule organizing center | cytosol | ribosome | cytoskeleton | plasma membrane | cilium | plastid | thylakoid | external encapsulating structure | extracellular matrix | cytoplasmic vesicle | organelle | other cellular component | |||
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Aspect | Term | |
---|---|---|
Cellular Component | host cell mitochondrion | |
Cellular Component | host cell nucleus | |
Biological Process | apoptotic process | |
Biological Process | DNA-templated transcription | |
Biological Process | symbiont-mediated activation of host NF-kappaB cascade | |
Biological Process | symbiont-mediated arrest of host cell cycle during G2/M transition | |
Biological Process | viral genome replication |
Keywords
- Molecular function
- Biological process
Names & Taxonomy
Protein names
- Recommended nameProtein X
- Alternative names
Gene names
Organism names
- Organism
- Strains
- Taxonomic lineageViruses > Riboviria > Pararnavirae > Artverviricota > Revtraviricetes > Blubervirales > Hepadnaviridae > Orthohepadnavirus
- Virus hosts
Accessions
- Primary accessionO11883
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
Note: Mainly cytoplasmic as only a fraction is detected in the nucleus. In cytoplasm, a minor fraction associates with mitochondria or proteasomes.
Keywords
- Cellular component
PTM/Processing
Post-translational modification
A fraction may be phosphorylated in insect cells and HepG2 cells, a human hepatoblastoma cell line. Phosphorylated in vitro by host protein kinase C or mitogen-activated protein kinase. N-acetylated in insect cells.
Interaction
Subunit
May form homodimer. May interact with host CEBPA, CFLAR, CREB1, DDB1, E4F1, HBXIP, HSPD1/HSP60, NFKBIA, POLR2E and SMAD4. Interacts with host SMC5-SMC6 complex and induces its degradation.
Structure
Family & Domains
Features
Showing features for region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 68-117 | Mitochondrial targeting sequence | ||||
Sequence: PCALRFTSARRMETTVNAHRMLPKVLHKRTLGLSAMSTTDLEAYFKDCLF |
Sequence similarities
Belongs to the orthohepadnavirus protein X family.
Family and domain databases
Sequence
- Sequence statusComplete
- Length154
- Mass (Da)16,611
- Last updated1997-07-01 v1
- Checksum895800BDF24CEA17
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
U95551 EMBL· GenBank· DDBJ | AAB59970.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
JX898686 EMBL· GenBank· DDBJ | AGA16743.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
JX898689 EMBL· GenBank· DDBJ | AGA16764.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
JX898690 EMBL· GenBank· DDBJ | AGA16771.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
JX898691 EMBL· GenBank· DDBJ | AGA16778.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
JX898692 EMBL· GenBank· DDBJ | AGA16785.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
JX898694 EMBL· GenBank· DDBJ | AGA16799.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
MF967563 EMBL· GenBank· DDBJ | AUG90794.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AB210819 EMBL· GenBank· DDBJ | BAE93198.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
MK618438 EMBL· GenBank· DDBJ | QEX51856.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
MN507835 EMBL· GenBank· DDBJ | QHB12472.1 EMBL· GenBank· DDBJ | Genomic DNA |