Seroatlas · Human Serome Atlas

TOP3B

DNA topoisomerase 3-beta-1

Also known as: TOP3B_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
O95985
Gene
TOP3B
Ensembl
ENSG00000100038
Chromosome
22
Canonical length
862 aa
Protein class
Enzymes, Plasma proteins, Predicted intracellular proteins
Subcellular location
Nucleoplasm

OverviewNCBI Gene

This gene encodes a DNA topoisomerase, an enzyme that controls and alters the topologic states of DNA during transcription. This enzyme catalyzes the transient breaking and rejoining of a single strand of DNA which allows the strands to pass through one another, thus relaxing the supercoils and altering the topology of DNA. The enzyme interacts with DNA helicase SGS1 and plays a role in DNA recombination, cellular aging and maintenance of genome stability. Low expression of this gene may be related to higher survival rates in breast cancer patients. This gene has a pseudogene on chromosome 22. Alternate splicing results in multiple transcript variants. Additional alternatively spliced transcript variants of this gene have been described, but their full-length nature is not known. [provided by RefSeq, Aug 2013]

Canonical amino-acid sequenceUniProt

862 residues, UniProt reviewed canonical sequence.

>O95985|TOP3B
     1  MKTVLMVAEK PSLAQSIAKI LSRGSLSSHK GLNGACSVHE YTGTFAGQPV RFKMTSVCGH
    61  VMTLDFLGKY NKWDKVDPAE LFSQAPTEKK EANPKLNMVK FLQVEGRGCD YIVLWLDCDK
   121  EGENICFEVL DAVLPVMNKA HGGEKTVFRA RFSSITDTDI CNAMACLGEP DHNEALSVDA
   181  RQELDLRIGC AFTRFQTKYF QGKYGDLDSS LISFGPCQTP TLGFCVERHD KIQSFKPETY
   241  WVLQAKVNTD KDRSLLLDWD RVRVFDREIA QMFLNMTKLE KEAQVEATSR KEKAKQRPLA
   301  LNTVEMLRVA SSSLGMGPQH AMQTAERLYT QGYISYPRTE TTHYPENFDL KGSLRQQANH
   361  PYWADTVKRL LAEGINRPRK GHDAGDHPPI TPMKSATEAE LGGDAWRLYE YITRHFIATV
   421  SHDCKYLQST ISFRIGPELF TCSGKTVLSP GFTEVMPWQS VPLEESLPTC QRGDAFPVGE
   481  VKMLEKQTNP PDYLTEAELI TLMEKHGIGT DASIPVHINN ICQRNYVTVE SGRRLKPTNL
   541  GIVLVHGYYK IDAELVLPTI RSAVEKQLNL IAQGKADYRQ VLGHTLDVFK RKFHYFVDSI
   601  AGMDELMEVS FSPLAATGKP LSRCGKCHRF MKYIQAKPSR LHCSHCDETY TLPQNGTIKL
   661  YKELRCPLDD FELVLWSSGS RGKSYPLCPY CYNHPPFRDM KKGMGCNECT HPSCQHSLSM
   721  LGIGQCVECE SGVLVLDPTS GPKWKVACNK CNVVAHCFEN AHRVRVSADT CSVCEAALLD
   781  VDFNKAKSPL PGDETQHMGC VFCDPVFQEL VELKHAASCH PMHRGGPGRR QGRGRGRARR
   841  PPGKPNPRRP KDKMSALAAY FV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against TOP3B 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)
0.27
Highest tissue expression
23 nTPM

Expression across tissuesHPA

Tissue

  • spleen: 23 nTPM
  • ovary: 19 nTPM
  • small intestine: 16 nTPM
  • cervix: 16 nTPM
  • liver: 16 nTPM
  • cerebellum: 16 nTPM

Single-cell type

  • renal collecting duct intercalated cells: 20 nCPM
  • cardiomyocytes: 16 nCPM
  • proximal tubule cells: 15 nCPM
  • distal convoluted tubule cells: 13 nCPM
  • loop of henle epithelial cells: 13 nCPM
  • retinal horizontal cells: 12 nCPM

Immune cell

  • gdT-cell: 5.5 nTPM
  • plasmacytoid DC: 5.5 nTPM
  • naive B-cell: 4.9 nTPM
  • myeloid DC: 4.7 nTPM
  • memory B-cell: 4.5 nTPM
  • intermediate monocyte: 4.4 nTPM

Brain region

  • choroid plexus: 28 nTPM
  • white matter: 18 nTPM
  • cerebral cortex: 18 nTPM
  • cerebellum: 18 nTPM
  • basal ganglia: 16 nTPM
  • thalamus: 15 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)
0.54
gnomAD pLI
0
gnomAD missense Z
2.23
DepMap mean gene effect
-0.11
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 TOP3B 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 TOP3B as an antibody target. Whether an autoantibody or antibody against TOP3B could matter depends on whether native TOP3B is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

TOP3B 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 TOP3B as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/TOP3B. 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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