Seroatlas · Human Serome Atlas

IZUMO1

Izumo sperm-egg fusion protein 1

Also known as: IZUM1_HUMAN, IZUMO, MGC34799, OBF

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

Protein identityUniProt · HPA

UniProt accession
Q8IYV9
Gene
IZUMO1
Ensembl
ENSG00000182264
Chromosome
19
Canonical length
350 aa
Protein class
Predicted intracellular proteins, Predicted membrane proteins, Transporters
Quaternary structure
Homodimer

OverviewNCBI Gene

The sperm-specific protein Izumo, named for a Japanese shrine dedicated to marriage, is essential for sperm-egg plasma membrane binding and fusion (Inoue et al., 2005 [PubMed 15759005]).[supplied by OMIM, Mar 2008]

Canonical amino-acid sequenceUniProt

350 residues, UniProt reviewed canonical sequence.

>Q8IYV9|IZUMO1
     1  MGPHFTLLCA ALAGCLLPAE GCVICDPSVV LALKSLEKDY LPGHLDAKHH KAMMERVENA
    61  VKDFQELSLN EDAYMGVVDE ATLQKGSWSL LKDLKRITDS DVKGDLFVKE LFWMLHLQKE
   121  TFATYVARFQ KEAYCPNKCG VMLQTLIWCK NCKKEVHACR KSYDCGERNV EVPQMEDMIL
   181  DCELNWHQAS EGLTDYSFYR VWGNNTETLV SKGKEATLTK PMVGPEDAGS YRCELGSVNS
   241  SPATIINFHV TVLPKMIKEE KPSPNIVTPG EATTESSISL QPLQPEKMLA SRLLGLLICG
   301  SLALITGLTF AIFRRRKVID FIKSSLFGLG SGAAEQTQVP KEKATDSRQQ

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against IZUMO1 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
1
Mean surface accessibility (rSASA)
0.4
Highest tissue expression
18 nTPM

Expression across tissuesHPA

Tissue

  • testis: 18 nTPM
  • pancreas: 1.6 nTPM
  • stomach: 1 nTPM
  • lung: 0.8 nTPM
  • duodenum: 0.5 nTPM
  • epididymis: 0.4 nTPM

Single-cell type

  • early spermatids: 188 nCPM
  • late spermatids: 147 nCPM
  • late primary spermatocytes: 70 nCPM
  • parietal cells: 19 nCPM
  • retinal ganglion cells: 12 nCPM
  • tuft cells: 12 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

  • cerebellum: 1.8 nTPM
  • cerebral cortex: 0.9 nTPM
  • amygdala: 0.4 nTPM
  • pons: 0.4 nTPM
  • basal ganglia: 0.3 nTPM
  • medulla oblongata: 0.3 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about IZUMO1.

Disease | ImmuneIEDB

Conditions an epitope on IZUMO1 was assayed in.

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)
1.17
gnomAD pLI
0
gnomAD missense Z
1.1
DepMap mean gene effect
-0.07
DepMap dependency class
selective

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 IZUMO1 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 IZUMO1 as an antibody target. Whether an autoantibody or antibody against IZUMO1 could matter depends on whether native IZUMO1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

IZUMO1 is annotated at the cell surface, where native IZUMO1 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 IZUMO1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/IZUMO1. 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).

© 2026 · Seroatlas, Discover Oregon LLC · Terms of use

Loading the interactive Seroatlas protein explorer...