Seroatlas · Human Serome Atlas

TSPAN18

Tetraspanin-18

Also known as: TSN18_HUMAN, TSPAN

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

Protein identityUniProt · HPA

UniProt accession: Q96SJ8
Gene: TSPAN18
Ensembl: ENSG00000157570
Chromosome: 11
Canonical length: 248 aa
Protein class: Predicted membrane proteins, Transporters

OverviewNCBI Gene

Involved in regulation of sprouting angiogenesis. Predicted to be located in membrane. Predicted to be active in plasma membrane. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

248 residues, UniProt reviewed canonical sequence.

>Q96SJ8|TSPAN18
     1  MEGDCLSCMK YLMFVFNFFI FLGGACLLAI GIWVMVDPTG FREIVAANPL LLTGAYILLA
    61  MGGLLFLLGF LGCCGAVREN KCLLLFFFLF ILIIFLAELS AAILAFIFRE NLTREFFTKE
   121  LTKHYQGNND TDVFSATWNS VMITFGCCGV NGPEDFKFAS VFRLLTLDSE EVPEACCRRE
   181  PQSRDGVLLS REECLLGRSL FLNKQGCYTV ILNTFETYVY LAGALAIGVL AIELFAMIFA
   241  MCLFRGIQ

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against TSPAN18 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: 4
Mean surface accessibility (rSASA): 0.34
Highest tissue expression: 78 nTPM

Expression across tissuesHPA

Tissue

heart muscle: 78 nTPM
cerebellum: 51 nTPM
smooth muscle: 44 nTPM
colon: 43 nTPM
endometrium: 43 nTPM
adrenal gland: 41 nTPM

Single-cell type

platelets: 168 nCPM
lymphatic endothelial cells: 118 nCPM
vascular endothelial cells: 103 nCPM
adrenal cortex cells: 87 nCPM
proximal tubule cells: 77 nCPM
medullary thymic epithelial cells: 74 nCPM

Immune cell

total PBMC: 1.7 nTPM
eosinophil: 1.6 nTPM
naive CD4 T-cell: 1.3 nTPM
memory CD4 T-cell: 1.1 nTPM
MAIT T-cell: 0.8 nTPM
memory CD8 T-cell: 0.5 nTPM

Brain region

cerebellum: 67 nTPM
hippocampal formation: 57 nTPM
midbrain: 25 nTPM
thalamus: 24 nTPM
spinal cord: 21 nTPM
cerebral cortex: 18 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): 0.72
gnomAD pLI: 0.08
gnomAD missense Z: 0.8
DepMap mean gene effect: -0.03
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

transmembrane transporter binding

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of TSPAN18 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

ORAI1

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads TSPAN18 as an antibody target. Whether an autoantibody or antibody against TSPAN18 could matter depends on whether native TSPAN18 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

TSPAN18 is annotated at the cell surface, where native TSPAN18 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 TSPAN18 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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