Seroatlas · Human Serome Atlas

IZUMO1R

Sperm-egg fusion protein Juno

Also known as: Folbp3, FOLR4, JUNO, JUNO_HUMAN

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

Protein identityUniProt · HPA

UniProt accession: A6ND01
Gene: IZUMO1R
Ensembl: ENSG00000183560
Chromosome: 11
Canonical length: 250 aa
Protein class: Predicted intracellular proteins, Transporters

OverviewNCBI Gene

Enables signaling receptor activity. Involved in fusion of sperm to egg plasma membrane involved in single fertilization. Located in plasma membrane. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

250 residues, UniProt reviewed canonical sequence.

>A6ND01|IZUMO1R
     1  MACWWPLLLE LWTVMPTWAG DELLNICMNA KHHKRVPSPE DKLYEECIPW KDNACCTLTT
    61  SWEAHLDVSP LYNFSLFHCG LLMPGCRKHF IQAICFYECS PNLGPWIQPV GSLGWEVAPS
   121  GQGERVVNVP LCQEDCEEWW EDCRMSYTCK SNWRGGWDWS QGKNRCPKGA QCLPFSHYFP
   181  TPADLCEKTW SNSFKASPER RNSGRCLQKW FEPAQGNPNV AVARLFASSA PSWELSYTIM
   241  VCSLFLPFLS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against IZUMO1R 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): 0.33
Highest tissue expression: 0.3 nTPM

Expression across tissuesHPA

Tissue

adrenal gland: 0.3 nTPM
choroid plexus: 0.3 nTPM
lymph node: 0.3 nTPM
ovary: 0.2 nTPM
appendix: 0.1 nTPM
blood vessel: 0.1 nTPM

Single-cell type

oocytes: 4.6 nCPM
leydig cells: 0.1 nCPM
undifferentiated spermatogonia: 0.1 nCPM
adipocytes: 0 nCPM
adrenal cortex cells: 0 nCPM
adrenal medulla cells: 0 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: 0.9 nTPM
choroid plexus: 0.6 nTPM
cerebral cortex: 0.5 nTPM
hippocampal formation: 0.3 nTPM
pons: 0.3 nTPM
amygdala: 0.2 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): 1.94
gnomAD pLI: 0

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% 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 IZUMO1R 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 IZUMO1R as an antibody target. Whether an autoantibody or antibody against IZUMO1R could matter depends on whether native IZUMO1R is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

IZUMO1R is annotated at the cell surface, where native IZUMO1R 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 IZUMO1R as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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