Seroatlas · Human Serome Atlas

SMIM22

Small integral membrane protein 22

Also known as: CASIMO1, SIM22_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
K7EJ46
Gene
SMIM22
Ensembl
ENSG00000267795
Chromosome
16
Canonical length
83 aa
Protein class
Predicted membrane proteins
Subcellular location
Nucleoplasm,Cytosol

OverviewNCBI Gene

Involved in several processes, including lipid droplet formation; positive regulation of cell migration; and regulation of actin cytoskeleton organization. Predicted to be located in late endosome and membrane. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

83 residues, UniProt reviewed canonical sequence.

>K7EJ46|SMIM22
     1  MAVSTEELEA TVQEVLGRLK SHQFFQSTWD TVAFIVFLTF MGTVLLLLLL VVAHCCCCSS
    61  PGPRRESPRK ERPKGVDNLA LEP

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SMIM22 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
1
Mean surface accessibility (rSASA)
0.56
Highest tissue expression
178 nTPM

Expression across tissuesHPA

Tissue

  • colon: 178 nTPM
  • stomach: 157 nTPM
  • salivary gland: 126 nTPM
  • duodenum: 122 nTPM
  • pancreas: 121 nTPM
  • small intestine: 116 nTPM

Single-cell type

  • colonocytes: 2,039 nCPM
  • enterocytes: 1,488 nCPM
  • goblet cells: 1,211 nCPM
  • foveolar cells: 1,108 nCPM
  • gastric chief cells: 976 nCPM
  • parietal cells: 941 nCPM

Immune cell

  • basophil: 0.9 nTPM
  • neutrophil: 0.7 nTPM
  • eosinophil: 0.3 nTPM
  • naive B-cell: 0.3 nTPM
  • classical monocyte: 0.2 nTPM
  • memory CD4 T-cell: 0.2 nTPM

Brain region

  • cerebellum: 21 nTPM
  • white matter: 17 nTPM
  • medulla oblongata: 16 nTPM
  • cerebral cortex: 16 nTPM
  • pons: 15 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)
1.95
gnomAD pLI
0
gnomAD missense Z
-0.96
DepMap mean gene effect
0.16
DepMap dependency class
none

OntologyGO

Biological processes

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of SMIM22 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 SMIM22 as an antibody target. Whether an autoantibody or antibody against SMIM22 could matter depends on whether native SMIM22 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SMIM22 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 SMIM22 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SMIM22. 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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