Seroatlas · Human Serome Atlas

SMIM23

Small integral membrane protein 23

Also known as: C5orf50, LOC644994, SIM23_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
A6NLE4
Gene
SMIM23
Ensembl
ENSG00000185662
Chromosome
5
Canonical length
172 aa
Protein class
Predicted intracellular proteins

OverviewNCBI Gene

Predicted to be located in plasma membrane. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

172 residues, UniProt reviewed canonical sequence.

>A6NLE4|SMIM23
     1  MATQQVDSRR QVAAEQVAAQ LLERRRGSHC DDEKQTLLAL LILVLYLSTE IWGSSWEVSE
    61  RIRECNYYQN LAVPQGLEYQ TNEPSEEPIK TIRNWLKEKL HVFSEKLEEE VQQLEQLAWD
   121  LELWLDALLG EPHQEEHCST YKSHLWEWAW ALGREHKGGE GLLEISLSGA EL

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SMIM23 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)
0.57
Highest tissue expression
24 nTPM

Expression across tissuesHPA

Tissue

  • testis: 24 nTPM
  • spleen: 0.1 nTPM
  • adipose tissue: 0 nTPM
  • adrenal gland: 0 nTPM
  • amygdala: 0 nTPM
  • appendix: 0 nTPM

Single-cell type

  • early spermatids: 441 nCPM
  • late primary spermatocytes: 136 nCPM
  • late spermatids: 91 nCPM
  • sertoli cells: 2.9 nCPM
  • epicardial cells: 2.3 nCPM
  • pdcs: 1.3 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

  • white matter: 0.1 nTPM
  • amygdala: 0 nTPM
  • basal ganglia: 0 nTPM
  • cerebellum: 0 nTPM
  • cerebral cortex: 0 nTPM
  • choroid plexus: 0 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
gnomAD pLI
0.01
gnomAD missense Z
1.12

OntologyGO

Cellular components

Protein domainsUniProt · Pfam · InterPro

  • Protein of unknown function DUF4635
  • Domain of unknown function (DUF4635)

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads SMIM23 as an antibody target. Whether an autoantibody or antibody against SMIM23 could matter depends on whether native SMIM23 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SMIM23 is annotated at the cell surface, where native SMIM23 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 SMIM23 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SMIM23. 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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