HMGB1

UniProt ID: P09429
Organism: Homo sapiens
Review Status: COMPLETE
πŸ“ Provide Detailed Feedback

Gene Description

HMGB1 is a 215-amino acid non-histone chromatin protein containing two HMG-box DNA-binding domains (A-box and B-box) and an acidic C-terminal tail. It has dual functions: (1) Nuclear - binds and bends DNA, modulates chromatin architecture, regulates transcription, and participates in DNA repair (BER, MMR, NER) and V(D)J recombination; (2) Extracellular - acts as a danger-associated molecular pattern (DAMP)/alarmin released from necrotic or activated cells, signaling through TLR4, TLR2, RAGE, and CXCR4 (via CXCL12 heterocomplex). Its activity is redox-regulated: all-thiol HMGB1 is chemotactic, disulfide HMGB1 (C23-C45 bond) induces cytokine production, and fully oxidized HMGB1 is inactive.

Proposed New Ontology Terms

holdase chaperone activity

Definition: Binding to an unfolded or misfolded protein to prevent its aggregation without actively catalyzing refolding. The holdase maintains the client protein in a soluble, folding-competent state. This is mechanistically distinct from foldase activity (GO:0044183) and from carrier-holdase activity (GO:0140309).

Justification: HMGB1: recombinant HMGB1 suppresses chemically and heat-induced aggregation of model substrates in vitro and binds expanded polyglutamine, reducing polyQ aggregation in cells; this is a secondary, chaperone-like activity of a chromatin protein. Obsolete GO:0051082 captured binding only; GO:0044183 requires assisting folding, and GO:0140309 (relabelled 'unfolded protein holdase activity') keeps a carrier-specific definition requiring escort to an acceptor molecule or location, which is not demonstrated here. See go-ontology#30552. GO:0051787 misfolded protein binding is live but, like the obsolete GO:0051082, records client binding only and not the suppression of aggregation, so it does not capture the activity. The proposed parent is the molecular_function root because GO has no general chaperone-activity grouping term: GO:0044183 protein folding chaperone is itself a direct child of GO:0003674.

Parent term: molecular_function

Supporting Evidence:

Existing Annotations Review

GO Term Evidence Action Reason
GO:0005634 nucleus
IBA
GO_REF:0000033
ACCEPT
Summary: HMGB1 is predominantly nuclear in basal state and shuttles between nucleus and cytoplasm. UniProt confirms nuclear localization with multiple experimental references.
Reason: Core localization for HMGB1's chromatin-associated functions including DNA binding, transcription regulation, and DNA repair. Well-supported by IDA evidence (PMID:8339930, PMID:19223331).
Supporting Evidence:
UniProt:P09429
Note=In basal state predominantly nuclear
file:human/HMGB1/HMGB1-deep-research-falcon.md
model: Edison Scientific Literature
GO:0006338 chromatin remodeling
IBA
GO_REF:0000033
ACCEPT
Summary: HMGB1 modulates chromatin structure by binding DNA, bending it, and facilitating nucleosome dynamics. It can restructure canonical nucleosomes and counteract linker histone H1.
Reason: Core function of HMGB1. The protein binds DNA with preference for non-canonical structures, enhances DNA flexibility, and can displace histone H1 from bent DNA. This represents a fundamental evolved function of the HMGB family.
Supporting Evidence:
UniProt:P09429
Can restructure the canonical nucleosome leading to relaxation of structural constraints for transcription factor-binding (By similarity)
file:human/HMGB1/HMGB1-deep-research-falcon.md
HMGB1 deforms nucleosomal DNA and counteracts linker histone H1 suppression of DNA accessibility without displacing H1
GO:0007165 signal transduction
IEA
GO_REF:0000120
ACCEPT
Summary: HMGB1 participates in signal transduction when released extracellularly, activating TLR4, TLR2, RAGE, and CXCR4 pathways.
Reason: Extracellular HMGB1 is a bona fide signaling molecule that activates NF-kB, MAPK/ERK, PI3K/AKT pathways through multiple receptors. This is a core extracellular function.
Supporting Evidence:
UniProt:P09429
Disulfide HMGB1 binds to transmembrane receptors, such as AGER/RAGE, TLR2, TLR4 and probably TREM1, thus activating their signal transduction pathways
GO:0050918 positive chemotaxis
IEA
GO_REF:0000108
ACCEPT
Summary: All-thiol (fully reduced) HMGB1 forms a complex with CXCL12 that signals through CXCR4 to promote chemotaxis and inflammatory cell recruitment.
Reason: Core extracellular function of the reduced HMGB1 isoform. The CXCL12-HMGB1 heterocomplex promotes CXCR4-mediated chemotaxis of monocytes and other inflammatory cells.
Supporting Evidence:
UniProt:P09429
Fully reduced HGMB1 (which subsequently gets oxidized after release) in association with CXCL12 mediates the recruitment of inflammatory cells during the initial phase of tissue injury
GO:0000793 condensed chromosome
IEA
GO_REF:0000117
ACCEPT
Summary: HMGB1 associates with mitotic chromosomes, supported by IDA evidence (PMID:12925773).
Reason: HMGB1 is a chromatin-associated protein that remains bound to chromosomes during mitosis. This is consistent with its core role in chromatin architecture.
GO:0001938 positive regulation of endothelial cell proliferation
IEA
GO_REF:0000117
KEEP AS NON CORE
Summary: Extracellular HMGB1 has proangiogenic activity and can stimulate endothelial cell proliferation via RAGE signaling.
Reason: While HMGB1 does have proangiogenic effects, this is a downstream consequence of its alarmin/DAMP signaling function rather than a core evolved function. It represents a pleiotropic effect of extracellular HMGB1.
GO:0002250 adaptive immune response
IEA
GO_REF:0000043
KEEP AS NON CORE
Summary: HMGB1 participates in adaptive immunity by enhancing T cell activation and suppressing regulatory T cells.
Reason: HMGB1 modulates adaptive immunity as a downstream effect of its DAMP/alarmin signaling. This is a pleiotropic consequence rather than a core function.
GO:0002376 immune system process
IEA
GO_REF:0000043
ACCEPT
Summary: HMGB1 is involved in both innate and adaptive immune responses as an extracellular alarmin.
Reason: Extracellular HMGB1 signaling through TLR4, TLR2, and RAGE is a core function that activates immune responses. This broad term appropriately captures the immunological role.
GO:0003677 DNA binding
IEA
GO_REF:0000120
ACCEPT
Summary: HMGB1 binds DNA through its two HMG-box domains with preference for non-canonical DNA structures.
Reason: DNA binding is the fundamental molecular function of HMGB1. The HMG-box domains bind DNA and bend it, enabling chromatin remodeling and transcription factor access.
GO:0003684 damaged DNA binding
IEA
GO_REF:0000117
ACCEPT
Summary: HMGB1 binds damaged DNA and participates in DNA repair pathways including BER, MMR, and NER.
Reason: Core function. HMGB1 binds cisplatin-modified DNA and other damaged DNA structures, and is a cofactor in base excision repair (PMID:17803946) and mismatch repair (PMID:15014079).
GO:0003714 transcription corepressor activity
IEA
GO_REF:0000117
ACCEPT
Summary: HMGB1 can repress transcription, demonstrated for p53/p73-dependent transactivation (PMID:11748232) and class II genes via TBP interaction (PMID:8006019).
Reason: HMGB1 has documented transcription corepressor activity, shown experimentally in multiple contexts including p53-dependent transcription and MHC class II gene regulation.
GO:0005576 extracellular region
IEA
GO_REF:0000044
ACCEPT
Summary: HMGB1 is released extracellularly from necrotic cells (passively) or activated immune cells (actively) to function as a DAMP/alarmin.
Reason: Core localization for HMGB1's alarmin function. Extracellular release is essential for its signaling through TLR4, RAGE, and CXCR4.
GO:0005634 nucleus
IEA
GO_REF:0000120
ACCEPT
Summary: HMGB1 is predominantly nuclear in basal state, functioning as a chromatin-associated protein.
Reason: Core localization. Nucleus is the primary compartment for HMGB1's chromatin-related functions. Duplicate of IBA annotation but valid.
GO:0005694 chromosome
IEA
GO_REF:0000044
ACCEPT
Summary: HMGB1 associates with chromosomes as a chromatin architectural protein.
Reason: HMGB1 is a chromatin-associated protein that binds to chromosomes and modulates their structure. This is consistent with its core nuclear function.
GO:0005737 cytoplasm
IEA
GO_REF:0000120
ACCEPT
Summary: HMGB1 translocates to the cytoplasm from the nucleus, especially during autophagy stimulation and prior to secretion.
Reason: Valid localization. HMGB1 shuttles between nucleus and cytoplasm, and cytoplasmic localization is important for its secretion pathway and autophagy-related functions.
GO:0005768 endosome
IEA
GO_REF:0000044
ACCEPT
Summary: HMGB1 localizes to endosomes, involved in TLR9 activation and nucleic acid sensing.
Reason: HMGB1 is involved in endosomal translocation and activation of TLR9 in response to CpG-DNA. Endosomal localization is part of its immune sensing function.
GO:0005783 endoplasmic reticulum
IEA
GO_REF:0000044
ACCEPT
Summary: HMGB1 localizes to ER, particularly during SARS-CoV-2 infection where ORF3a promotes its translocation there.
Reason: Valid localization supported by IDA evidence (PMID:35239449). ER localization is part of HMGB1's secretory pathway and its role in ER stress responses.
GO:0005793 endoplasmic reticulum-Golgi intermediate compartment
IEA
GO_REF:0000044
ACCEPT
Summary: HMGB1 localizes to ERGIC as part of its non-classical secretory pathway.
Reason: HMGB1 is secreted via a non-classical pathway involving secretory lysosomes. ERGIC localization is consistent with this secretory mechanism.
GO:0005886 plasma membrane
IEA
GO_REF:0000044
ACCEPT
Summary: HMGB1 is found on the surface of activated platelets and can associate with cell membrane.
Reason: HMGB1 is found on the surface of activated platelets (PMID:11154118). Peripheral membrane association is documented.
GO:0006259 DNA metabolic process
IEA
GO_REF:0000117
ACCEPT
Summary: HMGB1 participates in DNA metabolism through its roles in replication, repair, and recombination.
Reason: Broad term that appropriately captures HMGB1's involvement in DNA replication, repair (BER, MMR, NER), and V(D)J recombination.
GO:0006281 DNA repair
IEA
GO_REF:0000043
ACCEPT
Summary: HMGB1 is a cofactor in multiple DNA repair pathways including BER, MMR, and NER.
Reason: Core nuclear function. HMGB1 is a cofactor in mammalian base excision repair (PMID:17803946), mismatch repair (PMID:15014079), and facilitates nucleotide excision repair (PMID:19446504).
GO:0006310 DNA recombination
IEA
GO_REF:0000043
ACCEPT
Summary: HMGB1 is involved in V(D)J recombination as a cofactor of the RAG complex.
Reason: Core function. HMGB1 stimulates RAG cleavage activity and is involved in V(D)J recombination (PMID:9166431).
GO:0006914 autophagy
IEA
GO_REF:0000043
MARK AS OVER ANNOTATED
Summary: Cytoplasmic HMGB1 promotes autophagy by binding Beclin-1 and displacing BCL2, but this is a secondary function.
Reason: While HMGB1 can promote autophagy via Beclin-1 interaction (PMID:20819940), this is a secondary/pleiotropic function, not its evolved core function. The core functions are chromatin biology (nuclear) and alarmin signaling (extracellular).
GO:0006935 chemotaxis
IEA
GO_REF:0000043
ACCEPT
Summary: All-thiol HMGB1 in complex with CXCL12 promotes chemotaxis of inflammatory cells via CXCR4.
Reason: Core extracellular function. The HMGB1-CXCL12 heterocomplex signals through CXCR4 to promote chemotaxis of monocytes and other inflammatory cells (PMID:22370717).
GO:0006954 inflammatory response
IEA
GO_REF:0000043
ACCEPT
Summary: Extracellular HMGB1 is a prototypical alarmin that promotes inflammatory responses through TLR4, TLR2, and RAGE.
Reason: Core extracellular function. Disulfide HMGB1 induces cytokine release (TNF, IL-1, IL-6, IL-8) through receptor activation (PMID:12765338).
GO:0006955 immune response
IEA
GO_REF:0000117
ACCEPT
Summary: HMGB1 participates in both innate and adaptive immune responses as a DAMP molecule.
Reason: Core function. HMGB1 is a danger-associated molecular pattern (DAMP) that amplifies immune responses during tissue injury.
GO:0006974 DNA damage response
IEA
GO_REF:0000043
ACCEPT
Summary: HMGB1 participates in DNA damage response as a cofactor in multiple repair pathways.
Reason: Core nuclear function. HMGB1 binds damaged DNA and participates in BER, MMR, and NER pathways.
GO:0008289 lipid binding
IEA
GO_REF:0000117
ACCEPT
Summary: HMGB1 binds phosphatidylserine and phosphatidylethanolamine on cell surfaces.
Reason: HMGB1 binds phosphatidylserine on apoptotic cells and inhibits their phagocytosis (PMID:18768881). This is part of its immunomodulatory function.
GO:0010596 negative regulation of endothelial cell migration
IEA
GO_REF:0000117
KEEP AS NON CORE
Summary: HMGB1 can negatively regulate endothelial cell migration through TLR4 and IRF3.
Reason: While HMGB1 can inhibit endothelial migration (PMID:23148224), this is a context-dependent pleiotropic effect rather than a core function.
GO:0032722 positive regulation of chemokine production
IEA
GO_REF:0000117
ACCEPT
Summary: Extracellular HMGB1 stimulates production of chemokines like CCL2, CCL3, CCL4, and CXCL10.
Reason: Core alarmin function. HMGB1 signaling through TLR4 and RAGE induces chemokine production as part of inflammatory response.
GO:0032732 positive regulation of interleukin-1 production
IEA
GO_REF:0000117
ACCEPT
Summary: HMGB1 stimulates IL-1 production via TLR4 signaling.
Reason: Core alarmin function. HMGB1 induces IL-1 production through receptor activation (PMID:12765338).
GO:0045087 innate immune response
IEA
GO_REF:0000043
ACCEPT
Summary: HMGB1 is a key mediator of innate immune responses as a DAMP/alarmin.
Reason: Core extracellular function. HMGB1 activates innate immune cells through TLR4, TLR2, TLR9, and RAGE signaling.
GO:0045597 positive regulation of cell differentiation
IEA
GO_REF:0000117
KEEP AS NON CORE
Summary: HMGB1 can promote cell differentiation including dendritic cell differentiation.
Reason: While HMGB1 promotes dendritic cell differentiation (PMID:15944249), this is a downstream pleiotropic effect of its alarmin signaling rather than a core function.
GO:0048018 receptor ligand activity
IEA
GO_REF:0000117
ACCEPT
Summary: Extracellular HMGB1 acts as a ligand for multiple receptors including TLR4, TLR2, RAGE, and CXCR4.
Reason: Core molecular function. HMGB1 is a bona fide receptor ligand that binds and activates TLR4, TLR2, RAGE, and works with CXCL12 to signal through CXCR4.
GO:0048468 cell development
IEA
GO_REF:0000117
KEEP AS NON CORE
Summary: HMGB1 may influence cell development through its chromatin and signaling functions.
Reason: This is a broad term capturing downstream effects. HMGB1 influences development through its transcriptional regulatory roles, but this is not a core evolved function.
GO:0050792 regulation of viral process
IEA
GO_REF:0000117
ACCEPT
Summary: HMGB1 regulates viral processes including SARS-CoV-2, influenza, dengue, and EBV infection.
Reason: HMGB1 is critical for coronavirus entry (PMID:33147444), promotes influenza replication (PMID:22696656), and facilitates dengue virus propagation (PMID:34971702).
GO:0051052 regulation of DNA metabolic process
IEA
GO_REF:0000117
ACCEPT
Summary: HMGB1 regulates DNA metabolism through its roles in repair, replication, and recombination.
Reason: Core function. HMGB1 is a DNA chaperone that regulates DNA repair, replication, and recombination.
GO:1903706 regulation of hemopoiesis
IEA
GO_REF:0000117
KEEP AS NON CORE
Summary: HMGB1 may regulate hematopoiesis through its immune signaling functions.
Reason: This is a downstream pleiotropic effect of HMGB1's alarmin signaling rather than a core evolved function.
GO:0005515 protein binding
IPI
PMID:15014079
Evidence for involvement of HMGB1 protein in human DNA misma...
MODIFY
Summary: HMGB1 interacts with MSH2 in DNA mismatch repair.
Reason: Protein binding is too vague. The interaction with MSH2 is functionally relevant to DNA repair.
Supporting Evidence:
PMID:15014079
2004 Mar 9. Evidence for involvement of HMGB1 protein in human DNA mismatch repair.
GO:0005515 protein binding
IPI
PMID:20819940
Endogenous HMGB1 regulates autophagy.
MODIFY
Summary: HMGB1 interacts with Beclin-1 in autophagy regulation.
Reason: Protein binding is too vague. The interaction with BECN1 is specific and functionally relevant.
Supporting Evidence:
PMID:20819940
Endogenous HMGB1 regulates autophagy.
GO:0005515 protein binding
IPI
PMID:23063560
HMGB1-facilitated p53 DNA binding occurs via HMG-Box/p53 tra...
MODIFY
Summary: HMGB1 interacts with p53 to facilitate p53-DNA binding.
Reason: Protein binding is too vague. Interaction with p53 is functionally important for transcription regulation.
Supporting Evidence:
PMID:23063560
2012 Oct 11. HMGB1-facilitated p53 DNA binding occurs via HMG-Box/p53 transactivation domain interaction, regulated by the acidic tail.
GO:0005515 protein binding
IPI
PMID:23303669
Chaperone-like activity of high-mobility group box 1 protein...
MODIFY
Summary: HMGB1 interacts with huntingtin (HTT) and has chaperone-like activity reducing polyQ aggregates.
Reason: Protein binding is too vague. This IPI row records binding to huntingtin (WITH/FROM UniProtKB:P42858), and the paper shows HMGB1 binding expanded polyglutamine, an aggregation-prone misfolded client, so misfolded protein binding is the informative binding term that IPI supports. The same paper's anti-aggregation assays support the proposed holdase chaperone activity term (see proposed_new_terms), which is an activity claim rather than a binding claim.
Proposed replacements: misfolded protein binding
Supporting Evidence:
PMID:23303669
HMGB1 directly interacted with polyQ on immunofluorescence and coimmunoprecipitation assay
GO:0005515 protein binding
IPI
PMID:24474694
An immunogenic peptide in the A-box of HMGB1 protein reverse...
MODIFY
Summary: HMGB1 interacts with RAGE receptor.
Reason: Protein binding is too vague. RAGE binding is core to HMGB1 alarmin function.
Proposed replacements: RAGE receptor binding
Supporting Evidence:
PMID:24474694
2014 Jan 28. An immunogenic peptide in the A-box of HMGB1 protein reverses apoptosis-induced tolerance through RAGE receptor.
GO:0005515 protein binding
IPI
PMID:25416956
A proteome-scale map of the human interactome network.
ACCEPT
Summary: High-throughput interactome study identifying HMGB1 interactions.
Reason: High-throughput interactome data provides valid evidence for protein binding capacity.
Supporting Evidence:
PMID:25416956
A proteome-scale map of the human interactome network.
GO:0005515 protein binding
IPI
PMID:28514442
Architecture of the human interactome defines protein commun...
ACCEPT
Summary: High-throughput interactome mapping.
Reason: High-throughput interactome data provides valid evidence for protein binding capacity.
Supporting Evidence:
PMID:28514442
Architecture of the human interactome defines protein communities and disease networks.
GO:0005515 protein binding
IPI
PMID:29721183
Delineating the HMGB1 and HMGB2 interactome in prostate and ...
ACCEPT
Summary: HMGB1/HMGB2 interactome in prostate and ovary cells.
Reason: Interactome study provides valid evidence for protein binding.
Supporting Evidence:
PMID:29721183
eCollection 2018 Apr 10.
GO:0005515 protein binding
IPI
PMID:31694235
Characterization of HMGB1/2 Interactome in Prostate Cancer b...
ACCEPT
Summary: HMGB1/2 interactome characterization by yeast two-hybrid.
Reason: Valid experimental evidence for protein binding capacity.
Supporting Evidence:
PMID:31694235
Characterization of HMGB1/2 Interactome in Prostate Cancer by Yeast Two Hybrid Approach: Potential Pathobiological Implications.
GO:0005515 protein binding
IPI
PMID:32296183
A reference map of the human binary protein interactome.
ACCEPT
Summary: Binary protein interactome reference map.
Reason: High-throughput interactome data provides valid evidence for protein binding.
Supporting Evidence:
PMID:32296183
Apr 8. A reference map of the human binary protein interactome.
GO:0005515 protein binding
IPI
PMID:32814053
Interactome Mapping Provides a Network of Neurodegenerative ...
ACCEPT
Summary: Interactome mapping of neurodegenerative disease proteins.
Reason: Valid interactome evidence.
Supporting Evidence:
PMID:32814053
Interactome Mapping Provides a Network of Neurodegenerative Disease Proteins and Uncovers Widespread Protein Aggregation in Affected Brains.
GO:0005515 protein binding
IPI
PMID:32867128
The HMGB1-2 Ovarian Cancer Interactome. The Role of HMGB Pro...
ACCEPT
Summary: HMGB1-2 ovarian cancer interactome.
Reason: Valid interactome evidence.
Supporting Evidence:
PMID:32867128
The HMGB1-2 Ovarian Cancer Interactome.
GO:0005515 protein binding
IPI
PMID:33961781
Dual proteome-scale networks reveal cell-specific remodeling...
ACCEPT
Summary: Dual proteome-scale networks.
Reason: High-throughput interactome data provides valid evidence for protein binding.
Supporting Evidence:
PMID:33961781
2021 May 6. Dual proteome-scale networks reveal cell-specific remodeling of the human interactome.
GO:0005515 protein binding
IPI
PMID:40205054
Multimodal cell maps as a foundation for structural and func...
ACCEPT
Summary: Multimodal cell maps interactome.
Reason: High-throughput interactome data.
Supporting Evidence:
PMID:40205054
Apr 9. Multimodal cell maps as a foundation for structural and functional genomics.
GO:0005515 protein binding
IPI
PMID:9472015
High mobility group protein-1 (HMG-1) is a unique activator ...
MODIFY
Summary: HMGB1 is a unique activator of p53 through direct interaction.
Reason: Protein binding is too vague. The p53 interaction is functionally important.
Proposed replacements: p53 binding
Supporting Evidence:
PMID:9472015
High mobility group protein-1 (HMG-1) is a unique activator of p53.
GO:0001773 myeloid dendritic cell activation
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: HMGB1 activates dendritic cells through RAGE signaling.
Reason: Downstream effect of HMGB1's alarmin signaling. DC activation is a consequence of receptor engagement, not a core function.
GO:0001935 endothelial cell proliferation
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: HMGB1 has proangiogenic activity affecting endothelial cells.
Reason: Pleiotropic effect of HMGB1 signaling through RAGE. Not a core evolved function.
GO:0002270 plasmacytoid dendritic cell activation
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: HMGB1 activates plasmacytoid dendritic cells, particularly with CpG-DNA.
Reason: Downstream effect of HMGB1's immune signaling function.
GO:0002281 macrophage activation involved in immune response
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 activates macrophages through TLR4 signaling.
Reason: Macrophage activation is a direct and well-documented effect of HMGB1 signaling through TLR4.
GO:0002643 regulation of tolerance induction
IEA
GO_REF:0000107
ACCEPT
Summary: Oxidized HMGB1 from apoptotic cells promotes immunological tolerance.
Reason: Sulfonyl HMGB1 from apoptotic cells promotes tolerance (PMID:18631454). This is part of HMGB1's redox-regulated immunomodulatory function.
GO:0002840 regulation of T cell mediated immune response to tumor cell
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: HMGB1 regulates T cell responses to tumors.
Reason: Pleiotropic effect of HMGB1's immune signaling. Context-dependent and not a core function.
GO:0003690 double-stranded DNA binding
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 binds double-stranded DNA through its HMG-box domains.
Reason: Core molecular function. The HMG-box domains bind dsDNA with preference for bent or distorted structures.
GO:0003725 double-stranded RNA binding
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 can bind double-stranded RNA.
Reason: HMGB1 is proposed as a universal biosensor for nucleic acids, including RNA. HDA evidence supports RNA binding (PMID:22658674, PMID:22681889).
GO:0003727 single-stranded RNA binding
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 can bind single-stranded RNA as part of its nucleic acid sensing function.
Reason: HMGB1 binds various nucleic acids including ssRNA. HDA evidence supports RNA binding (PMID:22658674, PMID:22681889).
GO:0005125 cytokine activity
IEA
GO_REF:0000107
ACCEPT
Summary: Disulfide HMGB1 acts as a cytokine, inducing production of inflammatory mediators.
Reason: Core extracellular function. Disulfide HMGB1 has cytokine-like activity, inducing TNF, IL-1, IL-6 release from immune cells.
GO:0005615 extracellular space
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 is released into extracellular space from necrotic or activated cells.
Reason: Core localization for alarmin function. Extensively documented with IDA evidence (PMID:19841752, PMID:25595774).
GO:0005769 early endosome
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 localizes to early endosomes as part of its TLR9 activation pathway.
Reason: HMGB1 is involved in endosomal translocation and activation of TLR9. Valid localization.
GO:0006284 base-excision repair
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 is a cofactor in mammalian base excision repair.
Reason: Core nuclear function. HMGB1 is a cofactor in BER, interacting with POLB, FEN1, and APE1 (PMID:17803946).
GO:0006325 chromatin organization
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 is a chromatin architectural protein that modulates chromatin structure.
Reason: Core nuclear function. HMGB1 binds DNA, bends it, and facilitates nucleosome dynamics.
GO:0010508 positive regulation of autophagy
IEA
GO_REF:0000120
MARK AS OVER ANNOTATED
Summary: Cytoplasmic HMGB1 promotes autophagy through Beclin-1 interaction.
Reason: While HMGB1 can promote autophagy via Beclin-1 (PMID:20819940), this is a secondary/pleiotropic function, not its evolved core function.
GO:0010858 calcium-dependent protein kinase regulator activity
IEA
GO_REF:0000107
UNDECIDED
Summary: Evidence for HMGB1 regulating calcium-dependent protein kinases is limited.
Reason: Limited direct evidence for this specific activity. Requires further investigation.
GO:0030295 protein kinase activator activity
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: HMGB1 activates kinase cascades (MAPK, ERK, JNK) through receptor signaling.
Reason: Kinase activation is an indirect downstream effect of HMGB1 receptor signaling, not a direct molecular function.
GO:0032727 positive regulation of interferon-alpha production
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 promotes IFN-alpha production through TLR9 activation in plasmacytoid DCs.
Reason: Part of HMGB1's innate immune signaling function. HMGB1 with CpG-DNA activates TLR9-mediated interferon production.
GO:0032728 positive regulation of interferon-beta production
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 promotes IFN-beta production through innate immune signaling.
Reason: Part of HMGB1's innate immune function via TLR signaling.
GO:0032731 positive regulation of interleukin-1 beta production
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 induces IL-1beta production through TLR4 and inflammasome activation.
Reason: Core alarmin function. Disulfide HMGB1 induces IL-1beta production through TLR4 signaling and inflammasome priming.
GO:0032755 positive regulation of interleukin-6 production
IEA
GO_REF:0000120
ACCEPT
Summary: HMGB1 induces IL-6 production from immune cells.
Reason: Core alarmin function. Well-documented cytokine induction by HMGB1 (PMID:12765338, PMID:26961863).
GO:0032760 positive regulation of tumor necrosis factor production
IEA
GO_REF:0000120
ACCEPT
Summary: HMGB1 induces TNF production through TLR4 signaling.
Reason: Core alarmin function. TNF induction is a well-documented effect of HMGB1 (PMID:12765338).
GO:0034137 positive regulation of toll-like receptor 2 signaling pathway
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 activates TLR2 signaling, especially with lipoteichoic acid.
Reason: Core alarmin function. HMGB1 binds lipoteichoic acid and transfers it to CD14 for TLR2 signaling.
GO:0034145 positive regulation of toll-like receptor 4 signaling pathway
IEA
GO_REF:0000107
ACCEPT
Summary: Disulfide HMGB1 binds TLR4-MD2 and activates signaling.
Reason: Core alarmin function. TLR4 is the primary receptor for disulfide HMGB1's cytokine-inducing activity (PMID:20547845).
GO:0035767 endothelial cell chemotaxis
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: HMGB1 promotes endothelial cell chemotaxis as part of its proangiogenic activity.
Reason: Downstream pleiotropic effect of HMGB1's alarmin/RAGE signaling.
GO:0043005 neuron projection
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: HMGB1 localizes to neuron projections and promotes neuronal outgrowth via RAGE.
Reason: Neuronal localization and outgrowth promotion is a tissue-specific pleiotropic effect.
GO:0045089 positive regulation of innate immune response
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 is a key activator of innate immune responses through multiple TLRs and RAGE.
Reason: Core extracellular function. HMGB1 is a prototypical DAMP that activates innate immunity.
GO:0070374 positive regulation of ERK1 and ERK2 cascade
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 activates ERK1/2 signaling through RAGE and TLR4.
Reason: Well-documented downstream signaling of HMGB1-receptor activation.
GO:0071222 cellular response to lipopolysaccharide
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 binds LPS and enhances LPS-mediated cellular responses.
Reason: HMGB1 binds LPS and transfers it to CD14 for TLR4 signaling (PMID:18354232, PMID:21660935).
GO:0071639 positive regulation of monocyte chemotactic protein-1 production
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 induces MCP-1/CCL2 production.
Reason: Part of HMGB1's chemokine-inducing activity.
GO:0090303 positive regulation of wound healing
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: HMGB1 promotes wound healing through its proangiogenic and immune-modulatory effects.
Reason: Wound healing promotion is a downstream pleiotropic effect of HMGB1's alarmin signaling.
GO:1901224 positive regulation of non-canonical NF-kappaB signal transduction
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 activates NF-kappaB signaling through RAGE and TLR4.
Reason: NF-kappaB activation is a well-documented downstream effect of HMGB1 receptor signaling.
GO:1903672 positive regulation of sprouting angiogenesis
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: HMGB1 has proangiogenic activity promoting sprouting angiogenesis.
Reason: Angiogenesis promotion is a downstream pleiotropic effect of HMGB1's RAGE signaling.
GO:2000819 regulation of nucleotide-excision repair
IEA
GO_REF:0000107
ACCEPT
Summary: HMGB1 may facilitate nucleotide excision repair through interaction with XPA and XPC.
Reason: HMGB1 interacts with XPA and XPC to facilitate NER (PMID:19446504).
GO:0005654 nucleoplasm
IDA
GO_REF:0000052
ACCEPT
Summary: HMGB1 localizes to nucleoplasm as a chromatin-associated protein.
Reason: Valid localization. HMGB1 is predominantly nuclear.
GO:0140656 endodeoxyribonuclease activator activity
IDA
PMID:17803946
HMGB1 is a cofactor in mammalian base excision repair.
ACCEPT
Summary: HMGB1 activates FEN1 endonuclease activity in base excision repair.
Reason: Core function in DNA repair. HMGB1 stimulates FEN1 endonuclease activity as part of BER (PMID:17803946).
Supporting Evidence:
PMID:17803946
HMGB1 is a cofactor in mammalian base excision repair.
GO:0006302 double-strand break repair
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 participates in double-strand break repair including NHEJ and V(D)J recombination.
Reason: Core nuclear function. Supported by sequence similarity to characterized orthologs.
GO:0005515 protein binding
IPI
PMID:35239449
SARS-CoV-2 ORF3a induces RETREG1/FAM134B-dependent reticulop...
ACCEPT
Summary: HMGB1 interacts with SARS-CoV-2 ORF3A protein.
Reason: Valid experimental evidence for protein interaction with viral protein.
Supporting Evidence:
PMID:35239449
2022 Mar 3. SARS-CoV-2 ORF3a induces RETREG1/FAM134B-dependent reticulophagy and triggers sequential ER stress and inflammatory responses during SARS-CoV-2 infection.
GO:0005783 endoplasmic reticulum
IDA
PMID:35239449
SARS-CoV-2 ORF3a induces RETREG1/FAM134B-dependent reticulop...
ACCEPT
Summary: HMGB1 localizes to ER during SARS-CoV-2 infection.
Reason: Valid IDA evidence for ER localization during viral infection.
Supporting Evidence:
PMID:35239449
2022 Mar 3. SARS-CoV-2 ORF3a induces RETREG1/FAM134B-dependent reticulophagy and triggers sequential ER stress and inflammatory responses during SARS-CoV-2 infection.
GO:0046598 positive regulation of viral entry into host cell
IMP
PMID:33147444
Genome-wide CRISPR Screens Reveal Host Factors Critical for ...
ACCEPT
Summary: HMGB1 is critical for SARS-CoV-2 and other coronavirus entry.
Reason: HMGB1 regulates expression of ACE2 and CTSL, promoting coronavirus entry (PMID:33147444).
Supporting Evidence:
PMID:33147444
Oct 20. Genome-wide CRISPR Screens Reveal Host Factors Critical for SARS-CoV-2 Infection.
GO:0005515 protein binding
IPI
PMID:15379539
The long acidic tail of high mobility group box 1 (HMGB1) pr...
ACCEPT
Summary: HMGB1 interacts with various proteins in a high-throughput study.
Reason: Valid high-throughput interactome evidence.
Supporting Evidence:
PMID:15379539
The long acidic tail of high mobility group box 1 (HMGB1) protein forms an extended and flexible structure that interacts with specific residues within and between the HMG boxes.
GO:0031507 heterochromatin formation
IGI
PMID:19158276
Chromatin-specific remodeling by HMGB1 and linker histone H1...
KEEP AS NON CORE
Summary: HMGB1 may be involved in heterochromatin formation.
Reason: Chromatin-related function but not a core activity. May be secondary to general chromatin architectural role.
Supporting Evidence:
PMID:19158276
Jan 21. Chromatin-specific remodeling by HMGB1 and linker histone H1 silences proinflammatory genes during endotoxin tolerance.
GO:0000122 negative regulation of transcription by RNA polymerase II
IDA
PMID:11748232
HMGB1 and HMGB2 cell-specifically down-regulate the p53- and...
ACCEPT
Summary: HMGB1 represses p53/p73-dependent transactivation of Bax and p21 promoters.
Reason: Core transcription regulatory function. HMGB1 can repress transcription as demonstrated for p53/p73-dependent genes (PMID:11748232).
Supporting Evidence:
PMID:11748232
Dec 17. HMGB1 and HMGB2 cell-specifically down-regulate the p53- and p73-dependent sequence-specific transactivation from the human Bax gene promoter.
GO:0003714 transcription corepressor activity
IDA
PMID:11748232
HMGB1 and HMGB2 cell-specifically down-regulate the p53- and...
ACCEPT
Summary: HMGB1 has transcription corepressor activity inhibiting p53/p73 transactivation.
Reason: Valid IDA evidence. HMGB1 acts as a corepressor for p53/p73-dependent transcription (PMID:11748232).
Supporting Evidence:
PMID:11748232
Dec 17. HMGB1 and HMGB2 cell-specifically down-regulate the p53- and p73-dependent sequence-specific transactivation from the human Bax gene promoter.
GO:0061629 RNA polymerase II-specific DNA-binding transcription factor binding
IPI
PMID:19223331
HMGB1 and HMGB2 proteins up-regulate cellular expression of ...
ACCEPT
Summary: HMGB1 binds transcription factors to facilitate their DNA binding.
Reason: Core function. HMGB1 interacts with and enhances binding of various transcription factors including p53, SREBPs, and others.
Supporting Evidence:
PMID:19223331
Feb 17. HMGB1 and HMGB2 proteins up-regulate cellular expression of human topoisomerase IIalpha.
GO:0005615 extracellular space
IDA
PMID:25595774
Cutting Edge: identification of neutrophil PGLYRP1 as a liga...
ACCEPT
Summary: HMGB1 is released to extracellular space as an alarmin.
Reason: Core localization for HMGB1's DAMP function. Well-documented extracellular release.
Supporting Evidence:
PMID:25595774
2015 Jan 16. Cutting Edge: identification of neutrophil PGLYRP1 as a ligand for TREM-1.
GO:0048018 receptor ligand activity
IDA
PMID:17568691
Endogenous signals released from necrotic cells augment infl...
ACCEPT
Summary: HMGB1 acts as a ligand for TLR4, TLR2, RAGE receptors.
Reason: Core molecular function. HMGB1 is a bona fide receptor ligand for multiple immune receptors (PMID:17568691).
Supporting Evidence:
PMID:17568691
2007 May 25. Endogenous signals released from necrotic cells augment inflammatory responses to bacterial endotoxin.
GO:0006303 double-strand break repair via nonhomologous end joining
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 participates in NHEJ DNA repair.
Reason: Core nuclear function supported by sequence similarity.
GO:0010508 positive regulation of autophagy
IMP
PMID:20819940
Endogenous HMGB1 regulates autophagy.
MARK AS OVER ANNOTATED
Summary: HMGB1 promotes autophagy through Beclin-1 interaction.
Reason: While HMGB1 can promote autophagy via Beclin-1 (PMID:20819940), this is a secondary/pleiotropic function, not a core evolved function. Core functions are chromatin biology and alarmin signaling.
Supporting Evidence:
PMID:20819940
Endogenous HMGB1 regulates autophagy.
GO:0003713 transcription coactivator activity
IDA
PMID:19223331
HMGB1 and HMGB2 proteins up-regulate cellular expression of ...
ACCEPT
Summary: HMGB1 has transcription coactivator activity enhancing transcription factor binding.
Reason: Core nuclear function. HMGB1 enhances binding and activity of various transcription factors (PMID:19223331).
Supporting Evidence:
PMID:19223331
Feb 17. HMGB1 and HMGB2 proteins up-regulate cellular expression of human topoisomerase IIalpha.
GO:0005615 extracellular space
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 is released to extracellular space.
Reason: Core localization for alarmin function. Supported by sequence similarity.
GO:0005634 nucleus
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 localizes to nucleus.
Reason: Core localization. Supported by sequence similarity to characterized orthologs.
GO:0071222 cellular response to lipopolysaccharide
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 mediates cellular response to LPS.
Reason: HMGB1 binds LPS and enhances TLR4-mediated responses. Supported by ISS.
GO:0000122 negative regulation of transcription by RNA polymerase II
IMP
PMID:19158276
Chromatin-specific remodeling by HMGB1 and linker histone H1...
ACCEPT
Summary: HMGB1 represses transcription in specific contexts.
Reason: Valid IMP evidence for transcription repression function.
Supporting Evidence:
PMID:19158276
Jan 21. Chromatin-specific remodeling by HMGB1 and linker histone H1 silences proinflammatory genes during endotoxin tolerance.
GO:0000122 negative regulation of transcription by RNA polymerase II
IGI
PMID:19158276
Chromatin-specific remodeling by HMGB1 and linker histone H1...
ACCEPT
Summary: HMGB1 involved in transcription repression.
Reason: Valid IGI evidence supporting transcription regulatory function.
Supporting Evidence:
PMID:19158276
Jan 21. Chromatin-specific remodeling by HMGB1 and linker histone H1 silences proinflammatory genes during endotoxin tolerance.
GO:0000976 transcription cis-regulatory region binding
IDA
PMID:19158276
Chromatin-specific remodeling by HMGB1 and linker histone H1...
ACCEPT
Summary: HMGB1 binds cis-regulatory regions of DNA.
Reason: Core function. HMGB1 binds DNA including regulatory regions to modulate transcription.
Supporting Evidence:
PMID:19158276
Jan 21. Chromatin-specific remodeling by HMGB1 and linker histone H1 silences proinflammatory genes during endotoxin tolerance.
GO:0017053 transcription repressor complex
IDA
PMID:19158276
Chromatin-specific remodeling by HMGB1 and linker histone H1...
ACCEPT
Summary: HMGB1 is part of transcription repressor complexes.
Reason: Valid IDA evidence. HMGB1 can participate in transcription repressor complexes.
Supporting Evidence:
PMID:19158276
Jan 21. Chromatin-specific remodeling by HMGB1 and linker histone H1 silences proinflammatory genes during endotoxin tolerance.
GO:0043536 positive regulation of blood vessel endothelial cell migration
IMP
PMID:28276476
miR-193a-3p interaction with HMGB1 downregulates human endot...
KEEP AS NON CORE
Summary: HMGB1 promotes endothelial cell migration as part of proangiogenic activity.
Reason: Downstream pleiotropic effect of HMGB1's RAGE signaling.
Supporting Evidence:
PMID:28276476
miR-193a-3p interaction with HMGB1 downregulates human endothelial cell proliferation and migration.
GO:1905564 positive regulation of vascular endothelial cell proliferation
IMP
PMID:28276476
miR-193a-3p interaction with HMGB1 downregulates human endot...
KEEP AS NON CORE
Summary: HMGB1 promotes vascular endothelial cell proliferation.
Reason: Downstream pleiotropic effect of HMGB1's proangiogenic signaling through RAGE.
Supporting Evidence:
PMID:28276476
miR-193a-3p interaction with HMGB1 downregulates human endothelial cell proliferation and migration.
GO:0005178 integrin binding
IDA
PMID:20826760
HMGB1 inhibits macrophage activity in efferocytosis through ...
ACCEPT
Summary: HMGB1 binds alphav-beta3 integrin.
Reason: Valid IDA evidence. Integrin binding is part of HMGB1's extracellular signaling repertoire.
Supporting Evidence:
PMID:20826760
HMGB1 inhibits macrophage activity in efferocytosis through binding to the alphavbeta3-integrin.
GO:0035868 alphav-beta3 integrin-HMGB1 complex
IDA
PMID:20826760
HMGB1 inhibits macrophage activity in efferocytosis through ...
ACCEPT
Summary: HMGB1 forms complex with alphav-beta3 integrin.
Reason: Valid IDA evidence for this specific protein complex (PMID:20826760).
Supporting Evidence:
PMID:20826760
HMGB1 inhibits macrophage activity in efferocytosis through binding to the alphavbeta3-integrin.
GO:2000426 negative regulation of apoptotic cell clearance
IDA
PMID:20826760
HMGB1 inhibits macrophage activity in efferocytosis through ...
ACCEPT
Summary: HMGB1 inhibits phagocytosis of apoptotic cells.
Reason: HMGB1 binds phosphatidylserine on apoptotic cells and inhibits their clearance (PMID:20826760).
Supporting Evidence:
PMID:20826760
HMGB1 inhibits macrophage activity in efferocytosis through binding to the alphavbeta3-integrin.
GO:0034774 secretory granule lumen
TAS
Reactome:R-HSA-6798748
ACCEPT
Summary: HMGB1 localizes to secretory granule lumen.
Reason: Valid TAS evidence. HMGB1 is secreted via secretory lysosomes.
GO:1904813 ficolin-1-rich granule lumen
TAS
Reactome:R-HSA-6800434
ACCEPT
Summary: HMGB1 present in ficolin-1-rich granule lumen.
Reason: Valid Reactome TAS evidence for granule localization.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-166072
ACCEPT
Summary: HMGB1 localizes to extracellular region in TLR signaling context.
Reason: Core localization. Reactome pathway annotation for HMGB1 in TLR signaling.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-166082
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization for alarmin function. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-166091
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-166119
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-166284
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-166286
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-166362
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-166363
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-2201316
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-2201322
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-2262775
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-2262777
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-2559414
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-5432825
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-5602353
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-5602383
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-5602606
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-6804099
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-6804100
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-6805981
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-937022
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-937059
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-937079
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0032755 positive regulation of interleukin-6 production
IDA
PMID:26961863
AGEs and HMGB1 Increase Inflammatory Cytokine Production fro...
ACCEPT
Summary: HMGB1 induces IL-6 production.
Reason: Core alarmin function. Well-documented cytokine induction (PMID:26961863).
Supporting Evidence:
PMID:26961863
Mar 9. AGEs and HMGB1 Increase Inflammatory Cytokine Production from Human Placental Cells, Resulting in an Enhancement of Monocyte Migration.
GO:0032757 positive regulation of interleukin-8 production
IDA
PMID:26961863
AGEs and HMGB1 Increase Inflammatory Cytokine Production fro...
ACCEPT
Summary: HMGB1 induces IL-8/CXCL8 production.
Reason: Core alarmin function. Part of cytokine-inducing activity (PMID:26961863).
Supporting Evidence:
PMID:26961863
Mar 9. AGEs and HMGB1 Increase Inflammatory Cytokine Production from Human Placental Cells, Resulting in an Enhancement of Monocyte Migration.
GO:2000343 positive regulation of chemokine (C-X-C motif) ligand 2 production
IDA
PMID:26961863
AGEs and HMGB1 Increase Inflammatory Cytokine Production fro...
ACCEPT
Summary: HMGB1 induces CXCL2 production.
Reason: Core alarmin function. Part of chemokine-inducing activity.
Supporting Evidence:
PMID:26961863
Mar 9. AGEs and HMGB1 Increase Inflammatory Cytokine Production from Human Placental Cells, Resulting in an Enhancement of Monocyte Migration.
GO:0001786 phosphatidylserine binding
IDA
PMID:18768881
High mobility group protein-1 inhibits phagocytosis of apopt...
ACCEPT
Summary: HMGB1 binds phosphatidylserine on apoptotic cells.
Reason: Valid IDA evidence. HMGB1 binds PS and inhibits apoptotic cell clearance (PMID:18768881).
Supporting Evidence:
PMID:18768881
High mobility group protein-1 inhibits phagocytosis of apoptotic neutrophils through binding to phosphatidylserine.
GO:0002840 regulation of T cell mediated immune response to tumor cell
ISS
GO_REF:0000024
KEEP AS NON CORE
Summary: HMGB1 regulates T cell responses to tumors.
Reason: Pleiotropic immune effect. Supported by ISS.
GO:0032689 negative regulation of type II interferon production
IDA
PMID:22473704
HMGB1 conveys immunosuppressive characteristics on regulator...
KEEP AS NON CORE
Summary: HMGB1 can suppress IFN-gamma production.
Reason: Context-dependent immunomodulatory effect (PMID:22473704).
Supporting Evidence:
PMID:22473704
HMGB1 conveys immunosuppressive characteristics on regulatory and conventional T cells.
GO:0032733 positive regulation of interleukin-10 production
IDA
PMID:22473704
HMGB1 conveys immunosuppressive characteristics on regulator...
KEEP AS NON CORE
Summary: HMGB1 induces IL-10 production.
Reason: Immunomodulatory effect. IL-10 induction is context-dependent (PMID:22473704).
Supporting Evidence:
PMID:22473704
HMGB1 conveys immunosuppressive characteristics on regulatory and conventional T cells.
GO:0032735 positive regulation of interleukin-12 production
IMP
PMID:15944249
Release of high mobility group box 1 by dendritic cells cont...
ACCEPT
Summary: HMGB1 induces IL-12 production from dendritic cells.
Reason: Part of HMGB1's DC activation and Th1 polarization function (PMID:15944249).
Supporting Evidence:
PMID:15944249
Release of high mobility group box 1 by dendritic cells controls T cell activation via the receptor for advanced glycation end products.
GO:0034165 positive regulation of toll-like receptor 9 signaling pathway
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 enhances TLR9 signaling.
Reason: Core alarmin function. HMGB1 facilitates TLR9 activation by CpG-DNA.
GO:0035711 T-helper 1 cell activation
IDA
PMID:22473704
HMGB1 conveys immunosuppressive characteristics on regulator...
KEEP AS NON CORE
Summary: HMGB1 activates Th1 cells.
Reason: Downstream effect of HMGB1's immune signaling. Context-dependent.
Supporting Evidence:
PMID:22473704
HMGB1 conveys immunosuppressive characteristics on regulatory and conventional T cells.
GO:0042104 positive regulation of activated T cell proliferation
IMP
PMID:15944249
Release of high mobility group box 1 by dendritic cells cont...
KEEP AS NON CORE
Summary: HMGB1 promotes T cell proliferation.
Reason: Downstream pleiotropic effect of HMGB1's DC activation (PMID:15944249).
Supporting Evidence:
PMID:15944249
Release of high mobility group box 1 by dendritic cells controls T cell activation via the receptor for advanced glycation end products.
GO:0043277 apoptotic cell clearance
IDA
PMID:18768881
High mobility group protein-1 inhibits phagocytosis of apopt...
ACCEPT
Summary: HMGB1 regulates apoptotic cell clearance by inhibiting phagocytosis.
Reason: Valid IDA evidence. HMGB1 binds PS on apoptotic cells and inhibits clearance (PMID:18768881).
Supporting Evidence:
PMID:18768881
High mobility group protein-1 inhibits phagocytosis of apoptotic neutrophils through binding to phosphatidylserine.
GO:0043371 negative regulation of CD4-positive, alpha-beta T cell differentiation
IDA
PMID:22473704
HMGB1 conveys immunosuppressive characteristics on regulator...
KEEP AS NON CORE
Summary: HMGB1 negatively regulates CD4 T cell differentiation.
Reason: Context-dependent immunomodulatory effect (PMID:22473704).
Supporting Evidence:
PMID:22473704
HMGB1 conveys immunosuppressive characteristics on regulatory and conventional T cells.
GO:0045063 T-helper 1 cell differentiation
IMP
PMID:15944249
Release of high mobility group box 1 by dendritic cells cont...
KEEP AS NON CORE
Summary: HMGB1 promotes Th1 differentiation.
Reason: Downstream effect of DC activation (PMID:15944249).
Supporting Evidence:
PMID:15944249
Release of high mobility group box 1 by dendritic cells controls T cell activation via the receptor for advanced glycation end products.
GO:0097350 neutrophil clearance
IDA
PMID:18768881
High mobility group protein-1 inhibits phagocytosis of apopt...
ACCEPT
Summary: HMGB1 regulates neutrophil clearance.
Reason: Valid IDA evidence related to apoptotic cell clearance (PMID:18768881).
Supporting Evidence:
PMID:18768881
High mobility group protein-1 inhibits phagocytosis of apoptotic neutrophils through binding to phosphatidylserine.
GO:2001200 positive regulation of dendritic cell differentiation
IMP
PMID:15944249
Release of high mobility group box 1 by dendritic cells cont...
KEEP AS NON CORE
Summary: HMGB1 promotes dendritic cell differentiation.
Reason: Downstream pleiotropic effect of alarmin signaling (PMID:15944249).
Supporting Evidence:
PMID:15944249
Release of high mobility group box 1 by dendritic cells controls T cell activation via the receptor for advanced glycation end products.
GO:0002643 regulation of tolerance induction
IDA
PMID:18631454
Induction of immunological tolerance by apoptotic cells requ...
ACCEPT
Summary: Oxidized HMGB1 from apoptotic cells promotes immune tolerance.
Reason: Valid IDA evidence. Sulfonyl HMGB1 promotes tolerance through Cys-106 oxidation (PMID:18631454).
Supporting Evidence:
PMID:18631454
Induction of immunological tolerance by apoptotic cells requires caspase-dependent oxidation of high-mobility group box-1 protein.
GO:0007204 positive regulation of cytosolic calcium ion concentration
IDA
PMID:22370717
HMGB1 promotes recruitment of inflammatory cells to damaged ...
KEEP AS NON CORE
Summary: HMGB1-CXCL12 complex induces calcium signaling via CXCR4.
Reason: Real but non-core: the cytosolic calcium increase is a downstream consequence of extracellular HMGB1-CXCL12 acting through the CXCR4 receptor, not a core function of HMGB1 (whose core roles are nuclear chromatin architecture / DNA bending and extracellular DAMP signaling). Surfaced by the ASSAY_TO_FUNCTION analysis (indirect ligand effect on a calcium readout).
Supporting Evidence:
PMID:22370717
HMGB1 promotes recruitment of inflammatory cells to damaged tissues by forming a complex with CXCL12 and signaling via CXCR4.
GO:0019958 C-X-C chemokine binding
IDA
PMID:22370717
HMGB1 promotes recruitment of inflammatory cells to damaged ...
ACCEPT
Summary: HMGB1 binds CXCL12 to form a heterocomplex.
Reason: Core function. HMGB1-CXCL12 binding is essential for CXCR4-mediated chemotaxis (PMID:22370717).
Supporting Evidence:
PMID:22370717
HMGB1 promotes recruitment of inflammatory cells to damaged tissues by forming a complex with CXCL12 and signaling via CXCR4.
GO:0070374 positive regulation of ERK1 and ERK2 cascade
IDA
PMID:22370717
HMGB1 promotes recruitment of inflammatory cells to damaged ...
ACCEPT
Summary: HMGB1-CXCL12 activates ERK1/2 via CXCR4.
Reason: Valid IDA evidence. ERK activation is part of CXCR4 signaling (PMID:22370717).
Supporting Evidence:
PMID:22370717
HMGB1 promotes recruitment of inflammatory cells to damaged tissues by forming a complex with CXCL12 and signaling via CXCR4.
GO:0090026 positive regulation of monocyte chemotaxis
IDA
PMID:22370717
HMGB1 promotes recruitment of inflammatory cells to damaged ...
ACCEPT
Summary: HMGB1-CXCL12 promotes monocyte chemotaxis.
Reason: Core extracellular function. Well-documented in PMID:22370717.
Supporting Evidence:
PMID:22370717
HMGB1 promotes recruitment of inflammatory cells to damaged tissues by forming a complex with CXCL12 and signaling via CXCR4.
GO:0003684 damaged DNA binding
IDA
PMID:17803946
HMGB1 is a cofactor in mammalian base excision repair.
ACCEPT
Summary: HMGB1 binds damaged DNA in base excision repair.
Reason: Core nuclear function. HMGB1 binds damaged DNA as part of BER (PMID:17803946).
Supporting Evidence:
PMID:17803946
HMGB1 is a cofactor in mammalian base excision repair.
GO:0016829 lyase activity
IDA
PMID:17803946
HMGB1 is a cofactor in mammalian base excision repair.
UNDECIDED
Summary: HMGB1 has lyase activity in BER context.
Reason: This annotation requires careful review. HMGB1 stimulates AP lyase activity but may not itself be the lyase.
Supporting Evidence:
PMID:17803946
HMGB1 is a cofactor in mammalian base excision repair.
GO:0032425 positive regulation of mismatch repair
IDA
PMID:15014079
Evidence for involvement of HMGB1 protein in human DNA misma...
ACCEPT
Summary: HMGB1 positively regulates mismatch repair.
Reason: Core nuclear function. HMGB1 is involved in MMR through MSH2 interaction (PMID:15014079).
Supporting Evidence:
PMID:15014079
2004 Mar 9. Evidence for involvement of HMGB1 protein in human DNA mismatch repair.
GO:0070182 DNA polymerase binding
IDA
PMID:17803946
HMGB1 is a cofactor in mammalian base excision repair.
ACCEPT
Summary: HMGB1 binds DNA polymerase beta in BER.
Reason: Valid IDA evidence. HMGB1 interacts with POLB in BER (PMID:17803946).
Supporting Evidence:
PMID:17803946
HMGB1 is a cofactor in mammalian base excision repair.
GO:0002218 activation of innate immune response
IDA
PMID:24971542
HMGB1-DNA complex-induced autophagy limits AIM2 inflammasome...
ACCEPT
Summary: HMGB1 activates innate immune response via AIM2 inflammasome.
Reason: Core alarmin function. HMGB1 promotes AIM2 inflammasome activation (PMID:24971542).
Supporting Evidence:
PMID:24971542
HMGB1-DNA complex-induced autophagy limits AIM2 inflammasome activation through RAGE.
GO:0032732 positive regulation of interleukin-1 production
IDA
PMID:12765338
Structural basis for the proinflammatory cytokine activity o...
ACCEPT
Summary: HMGB1 induces IL-1 production.
Reason: Core alarmin function. Well-documented cytokine induction (PMID:12765338).
Supporting Evidence:
PMID:12765338
Structural basis for the proinflammatory cytokine activity of high mobility group box 1.
GO:0032755 positive regulation of interleukin-6 production
IDA
PMID:12765338
Structural basis for the proinflammatory cytokine activity o...
ACCEPT
Summary: HMGB1 induces IL-6 production.
Reason: Core alarmin function. Well-documented (PMID:12765338).
Supporting Evidence:
PMID:12765338
Structural basis for the proinflammatory cytokine activity of high mobility group box 1.
GO:0032760 positive regulation of tumor necrosis factor production
IDA
PMID:12765338
Structural basis for the proinflammatory cytokine activity o...
ACCEPT
Summary: HMGB1 induces TNF production.
Reason: Core alarmin function. Well-documented (PMID:12765338).
Supporting Evidence:
PMID:12765338
Structural basis for the proinflammatory cytokine activity of high mobility group box 1.
GO:0043410 positive regulation of MAPK cascade
IDA
PMID:12765338
Structural basis for the proinflammatory cytokine activity o...
ACCEPT
Summary: HMGB1 activates MAPK signaling.
Reason: Valid IDA evidence. MAPK activation through receptor signaling (PMID:12765338).
Supporting Evidence:
PMID:12765338
Structural basis for the proinflammatory cytokine activity of high mobility group box 1.
GO:0046330 positive regulation of JNK cascade
IDA
PMID:12765338
Structural basis for the proinflammatory cytokine activity o...
ACCEPT
Summary: HMGB1 activates JNK signaling.
Reason: Valid IDA evidence. JNK activation through receptor signaling (PMID:12765338).
Supporting Evidence:
PMID:12765338
Structural basis for the proinflammatory cytokine activity of high mobility group box 1.
GO:0001530 lipopolysaccharide binding
IDA
PMID:21660935
Identification of lipopolysaccharide-binding peptide regions...
ACCEPT
Summary: HMGB1 binds LPS and transfers it to CD14.
Reason: Core function. HMGB1 binds LPS and enhances TLR4 signaling (PMID:21660935).
Supporting Evidence:
PMID:21660935
Aug 4. Identification of lipopolysaccharide-binding peptide regions within HMGB1 and their effects on subclinical endotoxemia in a mouse model.
GO:0000400 four-way junction DNA binding
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 binds four-way junction DNA structures.
Reason: Core function. HMGB1 preferentially binds non-canonical DNA structures including cruciform DNA.
GO:0000405 bubble DNA binding
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 binds bubble DNA structures.
Reason: Core function. HMGB1 binds distorted DNA structures.
GO:0008301 DNA binding, bending
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 binds and bends DNA.
Reason: Core molecular function. DNA bending is fundamental to HMGB1's chromatin function.
GO:0032392 DNA geometric change
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 induces DNA geometric changes.
Reason: Core function. HMGB1 bends DNA and alters its geometry.
GO:0097100 supercoiled DNA binding
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 binds supercoiled DNA.
Reason: Core function. HMGB1 preferentially binds non-canonical DNA including supercoiled DNA.
GO:0003723 RNA binding
HDA
PMID:22658674
Insights into RNA biology from an atlas of mammalian mRNA-bi...
ACCEPT
Summary: HMGB1 binds RNA as a nucleic acid biosensor.
Reason: HMGB1 binds various nucleic acids including RNA. HDA evidence from interactome capture.
Supporting Evidence:
PMID:22658674
May 31. Insights into RNA biology from an atlas of mammalian mRNA-binding proteins.
GO:0003723 RNA binding
HDA
PMID:22681889
The mRNA-bound proteome and its global occupancy profile on ...
ACCEPT
Summary: HMGB1 binds RNA.
Reason: Valid HDA evidence from interactome studies (PMID:22681889).
Supporting Evidence:
PMID:22681889
The mRNA-bound proteome and its global occupancy profile on protein-coding transcripts.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-6798748
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-6800434
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-HSA-879411
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005576 extracellular region
TAS
Reactome:R-NUL-997411
ACCEPT
Summary: HMGB1 in extracellular region.
Reason: Core localization. Reactome TAS evidence.
GO:0005654 nucleoplasm
TAS
Reactome:R-HSA-266204
ACCEPT
Summary: HMGB1 in nucleoplasm.
Reason: Core localization. Reactome TAS evidence for V(D)J recombination.
GO:0005654 nucleoplasm
TAS
Reactome:R-HSA-6805981
ACCEPT
Summary: HMGB1 in nucleoplasm.
Reason: Core localization. Reactome TAS evidence.
GO:0006954 inflammatory response
IDA
PMID:23146691
Emodin-6-O-Ξ²-D-glucoside inhibits HMGB1-induced inflammatory...
ACCEPT
Summary: HMGB1 promotes inflammatory response.
Reason: Core alarmin function. Well-documented (PMID:23146691).
Supporting Evidence:
PMID:23146691
2012 Nov 9. Emodin-6-O-Ξ²-D-glucoside inhibits HMGB1-induced inflammatory responses in vitro and in vivo.
GO:0043537 negative regulation of blood vessel endothelial cell migration
IDA
PMID:23148224
High mobility group Box 1 inhibits human pulmonary artery en...
KEEP AS NON CORE
Summary: HMGB1 can inhibit endothelial migration via TLR4.
Reason: Context-dependent pleiotropic effect (PMID:23148224).
Supporting Evidence:
PMID:23148224
2012 Nov 12. High mobility group Box 1 inhibits human pulmonary artery endothelial cell migration via a Toll-like receptor 4- and interferon response factor 3-dependent mechanism(s).
GO:0005615 extracellular space
IDA
PMID:19841752
Linking innate and adaptive immunity: human Vgamma9Vdelta2 T...
ACCEPT
Summary: HMGB1 in extracellular space.
Reason: Core localization. IDA evidence.
Supporting Evidence:
PMID:19841752
Linking innate and adaptive immunity: human Vgamma9Vdelta2 T cells enhance CD40 expression and HMGB-1 secretion.
GO:0009986 cell surface
IDA
PMID:19841752
Linking innate and adaptive immunity: human Vgamma9Vdelta2 T...
ACCEPT
Summary: HMGB1 on cell surface.
Reason: Valid IDA evidence. HMGB1 on surface of activated cells (PMID:19841752).
Supporting Evidence:
PMID:19841752
Linking innate and adaptive immunity: human Vgamma9Vdelta2 T cells enhance CD40 expression and HMGB-1 secretion.
GO:0005515 protein binding
IPI
PMID:19505873
Complementary quantitative proteomics reveals that transcrip...
ACCEPT
Summary: HMGB1 binds proteins.
Reason: Valid IPI evidence from interactome study.
Supporting Evidence:
PMID:19505873
Epub 2009 Jun 7. Complementary quantitative proteomics reveals that transcription factor AP-4 mediates E-box-dependent complex formation for transcriptional repression of HDM2.
GO:0031175 neuron projection development
ISS
GO_REF:0000024
KEEP AS NON CORE
Summary: HMGB1 involved in neuron projection development via RAGE.
Reason: Tissue-specific pleiotropic effect through RAGE signaling.
GO:0043388 positive regulation of DNA binding
IDA
PMID:11748232
HMGB1 and HMGB2 cell-specifically down-regulate the p53- and...
ACCEPT
Summary: HMGB1 enhances DNA binding of transcription factors.
Reason: Core function. HMGB1 enhances DNA binding of p53 and other transcription factors (PMID:11748232).
Supporting Evidence:
PMID:11748232
Dec 17. HMGB1 and HMGB2 cell-specifically down-regulate the p53- and p73-dependent sequence-specific transactivation from the human Bax gene promoter.
GO:0050786 RAGE receptor binding
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 binds RAGE receptor.
Reason: Core alarmin function. RAGE binding is essential for many HMGB1 extracellular effects.
GO:0001773 myeloid dendritic cell activation
ISS
GO_REF:0000024
KEEP AS NON CORE
Summary: HMGB1 activates dendritic cells.
Reason: Downstream effect of alarmin signaling. ISS evidence.
GO:0002407 dendritic cell chemotaxis
ISS
GO_REF:0000024
KEEP AS NON CORE
Summary: HMGB1 promotes dendritic cell chemotaxis.
Reason: Downstream pleiotropic effect. ISS evidence.
GO:0002437 inflammatory response to antigenic stimulus
IEP
PMID:19841752
Linking innate and adaptive immunity: human Vgamma9Vdelta2 T...
ACCEPT
Summary: HMGB1 elevated during inflammatory response to antigen.
Reason: Valid IEP evidence. HMGB1 elevated in inflammatory contexts.
Supporting Evidence:
PMID:19841752
Linking innate and adaptive immunity: human Vgamma9Vdelta2 T cells enhance CD40 expression and HMGB-1 secretion.
GO:0003684 damaged DNA binding
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 binds damaged DNA.
Reason: Core function. ISS evidence supporting damaged DNA binding.
GO:0005125 cytokine activity
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 has cytokine activity.
Reason: Core extracellular function. Disulfide HMGB1 has cytokine-like activity. ISS evidence.
GO:0033151 V(D)J recombination
IDA
PMID:9166431
V(D)J recombination: modulation of RAG1 and RAG2 cleavage ac...
ACCEPT
Summary: HMGB1 is a cofactor in V(D)J recombination.
Reason: Core nuclear function. HMGB1 stimulates RAG cleavage in V(D)J recombination (PMID:9166431).
Supporting Evidence:
PMID:9166431
V(D)J recombination: modulation of RAG1 and RAG2 cleavage activity on 12/23 substrates by whole cell extract and DNA-bending proteins.
GO:0042056 chemoattractant activity
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 has chemoattractant activity.
Reason: Core extracellular function. All-thiol HMGB1 with CXCL12 is chemotactic. ISS evidence.
GO:0043065 positive regulation of apoptotic process
IDA
PMID:19800306
Effect of high mobility group box-1 protein on apoptosis of ...
KEEP AS NON CORE
Summary: HMGB1 can promote apoptosis in certain contexts.
Reason: Context-dependent effect (PMID:19800306). Not a core function.
Supporting Evidence:
PMID:19800306
Epub 2009 Oct 1. Effect of high mobility group box-1 protein on apoptosis of peritoneal macrophages.
GO:0003690 double-stranded DNA binding
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 binds double-stranded DNA through its HMG-box domains A and B. This is a well-established core function.
Reason: DNA binding is a fundamental function of HMGB1. The protein binds dsDNA through its HMG-box domains (PMID:8339930). ISS transfer from ortholog is appropriate.
Supporting Evidence:
PMID:8339930
The mammalian high mobility group proteins HMG1 and HMG2 are abundant, chromatin-associated proteins
GO:0003697 single-stranded DNA binding
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 has been shown to bind single-stranded DNA in addition to dsDNA through its HMG-box domains.
Reason: HMGB1 binds various DNA structures including ssDNA. ISS transfer from ortholog data is appropriate given the conserved DNA-binding HMG-box domains.
GO:0005515 protein binding
IPI
PMID:11748232
HMGB1 and HMGB2 cell-specifically down-regulate the p53- and...
MODIFY
Summary: This study demonstrates HMGB1 physically interacts with p53 and p73 transcription factors, enhancing their DNA binding. The generic protein binding term should be replaced with a more specific term.
Reason: HMGB1 interacts with p53 and p73 transcription factors to modulate their DNA binding activity (PMID:11748232). The generic protein binding term is uninformative; a more specific term for transcription factor binding is appropriate.
Supporting Evidence:
PMID:11748232
HMGB1 physically interacts with two splicing variants of p73, alpha and beta (pull-down assay), and enhances binding of p73 to specific cognate DNA sites
GO:0005634 nucleus
IDA
PMID:19223331
HMGB1 and HMGB2 proteins up-regulate cellular expression of ...
ACCEPT
Summary: HMGB1 is a chromatin-associated nuclear protein that shuttles between nucleus and cytoplasm. Nuclear localization is well-established.
Reason: Nuclear localization is a core characteristic of HMGB1 as a chromatin-associated protein (PMID:19223331). The protein is predominantly nuclear in basal state.
Supporting Evidence:
PMID:19223331
HMGB1 is associated with chromosomes in mitosis and due to its extreme mobility in the cell the protein is continuously exchanged between nucleus and cytoplasm
GO:0006265 DNA topological change
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 binding causes DNA bending and topological changes. The protein can promote DNA circularization and alter DNA topology.
Reason: HMGB1 induces DNA topological changes through its DNA-bending activity (PMID:8339930). This is a core biochemical function demonstrated by circularization assays.
Supporting Evidence:
PMID:8339930
HMG1 and HMG2 can bend DNA extremely efficiently, forming circles as small as 66 bp
GO:0006310 DNA recombination
ISS
GO_REF:0000024
ACCEPT
Summary: HMGB1 participates in DNA recombination including V(D)J recombination by facilitating DNA bending and promoting assembly of nucleoprotein complexes.
Reason: HMGB1 promotes DNA recombination by facilitating DNA flexibility and nucleoprotein complex assembly (PMID:8339930). This is a core nuclear function.
Supporting Evidence:
PMID:8339930
these proteins can substitute for the prokaryotic DNA-bending protein HU in promoting the assembly of the Hin invertasome, an intermediate structure in Hin-mediated site-specific DNA inversion
GO:0008301 DNA binding, bending
IMP
PMID:19223331
HMGB1 and HMGB2 proteins up-regulate cellular expression of ...
ACCEPT
Summary: HMGB1 DNA bending is a core function. The study showed that HMGB1, but not a mutant incapable of DNA bending, activates the topo IIalpha promoter.
Reason: DNA bending is a fundamental function of HMGB1 demonstrated by IMP evidence. The study shows DNA bending is required for HMGB1 to activate topo IIalpha promoter (PMID:19223331).
Supporting Evidence:
PMID:19223331
HMGB1, but not a mutant of HMGB1 incapable of DNA bending, up-regulates the activity of the topo IIalpha promoter in human cells
GO:0043388 positive regulation of DNA binding
IDA
PMID:19223331
HMGB1 and HMGB2 proteins up-regulate cellular expression of ...
ACCEPT
Summary: HMGB1 enhances DNA binding of transcription factors like NF-Y and p53/p73 family members by modulating DNA structure.
Reason: HMGB1 positively regulates DNA binding by modulating transcription factor NF-Y binding to promoters (PMID:19223331). This is a core function related to its transcriptional coregulator role.
Supporting Evidence:
PMID:19223331
Our experiments suggest a mechanism of up-regulation of cellular expression of topo IIalpha by HMGB1/2 in pRb-negative cells by modulation of binding of transcription factor NF-Y to the topo IIalpha promoter
GO:0045944 positive regulation of transcription by RNA polymerase II
IDA
PMID:19223331
HMGB1 and HMGB2 proteins up-regulate cellular expression of ...
ACCEPT
Summary: HMGB1 upregulates topo IIalpha promoter activity through luciferase reporter assays in pRb-negative cells.
Reason: HMGB1 positively regulates transcription by RNA pol II as demonstrated by luciferase reporter assays showing upregulation of topo IIalpha promoter (PMID:19223331). This is a core transcriptional coregulator function.
Supporting Evidence:
PMID:19223331
Using luciferase gene reporter assay we have demonstrated that HMGB1, but not a mutant of HMGB1 incapable of DNA bending, up-regulated the activity of human topo IIalpha promoter in human cells that lack functional retinoblastoma protein pRb
GO:0140297 DNA-binding transcription factor binding
IPI
PMID:19223331
HMGB1 and HMGB2 proteins up-regulate cellular expression of ...
ACCEPT
Summary: HMGB1 interacts with transcription factors including NF-Y to modulate their DNA binding activity and transcriptional output.
Reason: HMGB1 interacts with and modulates the activity of DNA-binding transcription factors like NF-Y (PMID:19223331) and p53/p73 family members. This is a specific and accurate molecular function term.
Supporting Evidence:
PMID:19223331
HMGB1 also interacts weakly with a number of proteins, including transcriptional factors, site-specific recombination and DNA repair proteins
GO:0005634 nucleus
IDA
PMID:8339930
The nonspecific DNA-binding and -bending proteins HMG1 and H...
ACCEPT
Summary: HMGB1 is an abundant chromatin-associated nuclear protein. Nuclear localization is fundamental to its function.
Reason: Nuclear localization is a core characteristic of HMGB1 as an abundant chromatin-associated protein (PMID:8339930). This is well-established and fundamental to its biological role.
Supporting Evidence:
PMID:8339930
The mammalian high mobility group proteins HMG1 and HMG2 are abundant, chromatin-associated proteins
GO:0000793 condensed chromosome
IDA
PMID:12925773
Association of chromatin proteins high mobility group box (H...
ACCEPT
Summary: HMGB1 associates with condensed chromosomes during mitosis. Live cell imaging shows the protein exchanges rapidly between free and chromosome-bound forms.
Reason: HMGB1 associates with condensed chromatin during mitosis as shown by fluorescent protein tagging in live cells (PMID:12925773). This is a core function related to its chromatin-binding role.
Supporting Evidence:
PMID:12925773
HMGB1 and 2 were shown to be present under two forms in mitotic cells, i.e., free and associated with the condensed chromatin, which rapidly exchange
GO:0005515 protein binding
IPI
PMID:8006019
The high mobility group protein HMG1 can reversibly inhibit ...
MODIFY
Summary: This study demonstrates HMGB1 physically interacts with TBP (TATA-binding protein) to inhibit preinitiation complex assembly. The generic term should be replaced with a more specific binding term.
Reason: HMGB1 interacts with TBP to form an HMG1.TBP.promoter complex that blocks TFIIB binding (PMID:8006019). The generic protein binding term is uninformative; a more specific term for transcription machinery component binding is appropriate.
Supporting Evidence:
PMID:8006019
purified mammalian HMG1, as well as recombinant human HMG1, can interact with TATA-binding protein (TBP) in the presence of a TATA box-containing oligonucleotide to form a specific HMG1.TBP.promoter complex
GO:0017055 negative regulation of RNA polymerase II transcription preinitiation complex assembly
IDA
PMID:8006019
The high mobility group protein HMG1 can reversibly inhibit ...
ACCEPT
Summary: HMGB1 interacts with TBP to form a complex that prevents TFIIB binding and blocks preinitiation complex formation. In vitro, HMGB1 inhibits transcription by RNA pol II over 30-fold.
Reason: HMGB1 inhibits preinitiation complex assembly by binding TBP and blocking TFIIB recruitment (PMID:8006019). This is a well-characterized transcriptional regulatory function with direct assay evidence.
Supporting Evidence:
PMID:8006019
This complex prevents TFIIB binding to TBP and consequently blocks formation of the preinitiation complex

Core Functions

HMGB1 binds and bends DNA through its two HMG-box domains (A and B). DNA bending is essential for its function as demonstrated by mutant studies showing that HMGB1 incapable of DNA bending fails to activate target promoters (PMID:19223331). The protein can bend DNA to form circles as small as 66 bp (PMID:8339930).

Molecular Function:
DNA binding, bending
Directly Involved In:
Cellular Locations:

HMGB1 acts as a transcriptional coregulator by binding transcription factors (p53, p73, NF-Y, TBP) and modulating their DNA binding activity. It can both positively and negatively regulate transcription depending on cellular context (PMID:8006019, PMID:19223331, PMID:11748232).

Extracellular HMGB1 acts as a DAMP/alarmin released from necrotic or activated cells, signaling through TLR4, TLR2, RAGE, and CXCR4 (via CXCL12 heterocomplex) to promote inflammation and chemotaxis. The all-thiol redox form is chemotactic, the disulfide form induces cytokine production, and the fully oxidized form is inactive.

Molecular Function:
cytokine activity
Directly Involved In:
Cellular Locations:

References

Loading supporting content…

Download this section (compressed HTML)

Deep Research

Falcon

(HMGB1-deep-research-falcon.md)

Loading supporting content…

Download this section (compressed HTML)

πŸ“„ View Raw YAML

Loading supporting content…

Download this section (compressed HTML)