Seroatlas · Human Serome Atlas

HMGB4

High mobility group protein B4

Also known as: FLJ40388, HMGB4_HUMAN

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession: Q8WW32
Gene: HMGB4
Ensembl: ENSG00000176256
Chromosome: 1
Canonical length: 186 aa
Protein class: Predicted intracellular proteins

OverviewNCBI Gene

Predicted to enable DNA binding activity, bending. Predicted to be involved in regulation of transcription by RNA polymerase II. Located in nucleus. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

186 residues, UniProt reviewed canonical sequence.

>Q8WW32|HMGB4
     1  MGKEIQLKPK ANVSSYVHFL LNYRNKFKEQ QPNTYVGFKE FSRKCSEKWR SISKHEKAKY
    61  EALAKLDKAR YQEEMMNYVG KRKKRRKRDP QEPRRPPSSF LLFCQDHYAQ LKRENPNWSV
   121  VQVAKATGKM WSTATDLEKH PYEQRVALLR AKYFEELELY RKQCNARKKY RMSARNRCRG
   181  KRVRQS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against HMGB4 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability: Intracellular
Secreted: No
Transmembrane segments: 0
Mean surface accessibility (rSASA): 0.44
Highest tissue expression: 557 nTPM

Expression across tissuesHPA

Tissue

testis: 557 nTPM
prostate: 0.4 nTPM
breast: 0.3 nTPM
adipose tissue: 0.1 nTPM
cerebellum: 0.1 nTPM
colon: 0.1 nTPM

Single-cell type

late spermatids: 28,225 nCPM
early spermatids: 13,375 nCPM
late primary spermatocytes: 2,821 nCPM
sertoli cells: 37 nCPM
leydig cells: 33 nCPM
undifferentiated spermatogonia: 16 nCPM

Immune cell

basophil: 0 nTPM
classical monocyte: 0 nTPM
eosinophil: 0 nTPM
gdT-cell: 0 nTPM
intermediate monocyte: 0 nTPM
MAIT T-cell: 0 nTPM

Brain region

cerebral cortex: 1.3 nTPM
hypothalamus: 1.3 nTPM
hippocampal formation: 1.1 nTPM
basal ganglia: 1 nTPM
pons: 1 nTPM
amygdala: 0.9 nTPM

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance): 1.91
gnomAD pLI: 0
gnomAD missense Z: -0.22
DepMap mean gene effect: 0.01
DepMap dependency class: none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

chromatin remodeling

Molecular functions

DNA binding

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads HMGB4 as an antibody target. Whether an autoantibody or antibody against HMGB4 could matter depends on whether native HMGB4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

HMGB4 is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label HMGB4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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