Seroatlas · Human Serome Atlas

DEF6

Differentially expressed in FDCP 6 homolog

Also known as: DEFI6_HUMAN, IBP, SLAT, SWAP70L

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

Protein identityUniProt · HPA

UniProt accession
Q9H4E7
Gene
DEF6
Ensembl
ENSG00000023892
Chromosome
6
Canonical length
631 aa
Protein class
Disease related genes, Human disease related genes, Predicted intracellular proteins
Subcellular location
Nucleoplasm

OverviewNCBI Gene

DEF6, or IBP, is a guanine nucleotide exchange factor (GEF) for RAC (MIM 602048) and CDC42 (MIM 116952) that is highly expressed in B and T cells (Gupta et al., 2003 [PubMed 12923183]).[supplied by OMIM, Mar 2008]

Canonical amino-acid sequenceUniProt

631 residues, UniProt reviewed canonical sequence.

>Q9H4E7|DEF6
     1  MALRKELLKS IWYAFTALDV EKSGKVSKSQ LKVLSHNLYT VLHIPHDPVA LEEHFRDDDD
    61  GPVSSQGYMP YLNKYILDKV EEGAFVKEHF DELCWTLTAK KNYRADSNGN SMLSNQDAFR
   121  LWCLFNFLSE DKYPLIMVPD EVEYLLKKVL SSMSLEVSLG ELEELLAQEA QVAQTTGGLS
   181  VWQFLELFNS GRCLRGVGRD TLSMAIHEVY QELIQDVLKQ GYLWKRGHLR RNWAERWFQL
   241  QPSCLCYFGS EECKEKRGII PLDAHCCVEV LPDRDGKRCM FCVKTANRTY EMSASDTRQR
   301  QEWTAAIQMA IRLQAEGKTS LHKDLKQKRR EQREQRERRR AAKEEELLRL QQLQEEKERK
   361  LQELELLQEA QRQAERLLQE EEERRRSQHR ELQQALEGQL REAEQARASM QAEMELKEEE
   421  AARQRQRIKE LEEMQQRLQE ALQLEVKARR DEESVRIAQT RLLEEEEEKL KQLMQLKEEQ
   481  ERYIERAQQE KEELQQEMAQ QSRSLQQAQQ QLEEVRQNRQ RADEDVEAAQ RKLRQASTNV
   541  KHWNVQMNRL MHPIEPGDKR PVTSSSFSGF QPPLLAHRDS SLKRLTRWGS QGNRTPSPNS
   601  NEQQKSLNGG DEAPAPASTP QEDKLDPAPE N

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against DEF6 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
Cell surface
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.41
Highest tissue expression
60 nTPM

Expression across tissuesHPA

Tissue

  • spleen: 60 nTPM
  • thymus: 37 nTPM
  • small intestine: 29 nTPM
  • lymph node: 27 nTPM
  • esophagus: 27 nTPM
  • skin: 27 nTPM

Single-cell type

  • late spermatids: 253 nCPM
  • hofbauer cells: 197 nCPM
  • neutrophils: 115 nCPM
  • neutrophil progenitors: 104 nCPM
  • late primary spermatocytes: 97 nCPM
  • microglia: 93 nCPM

Immune cell

  • eosinophil: 111 nTPM
  • gdT-cell: 73 nTPM
  • memory CD8 T-cell: 71 nTPM
  • NK-cell: 68 nTPM
  • T-reg: 68 nTPM
  • neutrophil: 61 nTPM

Brain region

  • medulla oblongata: 3.1 nTPM
  • white matter: 3.1 nTPM
  • pons: 2 nTPM
  • spinal cord: 1.9 nTPM
  • thalamus: 1.9 nTPM
  • hypothalamus: 1.5 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about DEF6.

Disease | AllUniProt

Conditions DEF6 is implicated in, by any mechanism.

  • Immunodeficiency 87 and autoimmunity (IMD87) MIM:619573

Disease | GeneticClinVar

9 pathogenic / likely-pathogenic of 396 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Immunodeficiency 87 and autoimmunity

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)
0.26
gnomAD pLI
1
gnomAD missense Z
3.03
DepMap mean gene effect
0
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% 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 DEF6 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 DEF6 as an antibody target. Whether an autoantibody or antibody against DEF6 could matter depends on whether native DEF6 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

DEF6 is annotated at the cell surface, where native DEF6 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label DEF6 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/DEF6. 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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