Seroatlas · Human Serome Atlas

CBX4

E3 SUMO-protein ligase CBX4

Also known as: CBX4_HUMAN, hPC2, NBP16, PC2

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

Protein identityUniProt · HPA

UniProt accession
O00257
Gene
CBX4
Ensembl
ENSG00000141582
Chromosome
17
Canonical length
560 aa
Protein class
Predicted intracellular proteins
Subcellular location
Nucleoplasm,Nuclear bodies

OverviewNCBI Gene

Enables SUMO binding activity; SUMO ligase activity; and enzyme binding activity. Involved in negative regulation of transcription by RNA polymerase II. Located in nuclear body. Part of PRC1 complex. Implicated in hepatocellular carcinoma. Biomarker of hepatocellular carcinoma. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

560 residues, UniProt reviewed canonical sequence.

>O00257|CBX4
     1  MELPAVGEHV FAVESIEKKR IRKGRVEYLV KWRGWSPKYN TWEPEENILD PRLLIAFQNR
    61  ERQEQLMGYR KRGPKPKPLV VQVPTFARRS NVLTGLQDSS TDNRAKLDLG AQGKGQGHQY
   121  ELNSKKHHQY QPHSKERAGK PPPPGKSGKY YYQLNSKKHH PYQPDPKMYD LQYQGGHKEA
   181  PSPTCPDLGA KSHPPDKWAQ GAGAKGYLGA VKPLAGAAGA PGKGSEKGPP NGMMPAPKEA
   241  VTGNGIGGKM KIVKNKNKNG RIVIVMSKYM ENGMQAVKIK SGEVAEGEAR SPSHKKRAAD
   301  ERHPPADRTF KKAAGAEEKK VEAPPKRREE EVSGVSDPQP QDAGSRKLSP TKEAFGEQPL
   361  QLTTKPDLLA WDPARNTHPP SHHPHPHPHH HHHHHHHHHH AVGLNLSHVR KRCLSETHGE
   421  REPCKKRLTA RSISTPTCLG GSPAAERPAD LPPAAALPQP EVILLDSDLD EPIDLRCVKT
   481  RSEAGEPPSS LQVKPETPAS AAVAVAAAAA PTTTAEKPPA EAQDEPAESL SEFKPFFGNI
   541  IITDVTANCL TVTFKEYVTV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CBX4 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)
0.67
Highest tissue expression
123 nTPM

Expression across tissuesHPA

Tissue

  • bone marrow: 123 nTPM
  • skin: 30 nTPM
  • thymus: 22 nTPM
  • liver: 20 nTPM
  • esophagus: 20 nTPM
  • spleen: 20 nTPM

Single-cell type

  • breast lactating cells: 233 nCPM
  • neutrophils: 182 nCPM
  • pdcs: 137 nCPM
  • neutrophil progenitors: 100 nCPM
  • müller glia: 97 nCPM
  • breast myoepithelial cells: 96 nCPM

Immune cell

  • neutrophil: 2.1 nTPM
  • eosinophil: 1.8 nTPM
  • plasmacytoid DC: 1.7 nTPM
  • basophil: 1.6 nTPM
  • memory B-cell: 1.5 nTPM
  • naive B-cell: 1.5 nTPM

Brain region

  • white matter: 50 nTPM
  • cerebral cortex: 41 nTPM
  • thalamus: 41 nTPM
  • medulla oblongata: 40 nTPM
  • basal ganglia: 38 nTPM
  • pons: 38 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)
0.28
gnomAD pLI
0.98
gnomAD missense Z
2.22
DepMap mean gene effect
-0.12
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 6% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of CBX4 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads CBX4 as an antibody target. Whether an autoantibody or antibody against CBX4 could matter depends on whether native CBX4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CBX4 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 CBX4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/CBX4. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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