Seroatlas · Human Serome Atlas

RPS18

Small ribosomal subunit protein uS13

Also known as: D6S218E, HKE3, KE-3, KE3, RS18_HUMAN, S18

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

Protein identityUniProt · HPA

UniProt accession
P62269
Gene
RPS18
Ensembl
ENSG00000231500
Chromosome
6
Canonical length
152 aa
Protein class
Plasma proteins, Predicted intracellular proteins, Ribosomal proteins
Subcellular location
Cytosol

OverviewNCBI Gene

Ribosomes, the organelles that catalyze protein synthesis, consist of a small 40S subunit and a large 60S subunit. Together these subunits are composed of 4 RNA species and approximately 80 structurally distinct proteins. This gene encodes a ribosomal protein that is a component of the 40S subunit. The protein belongs to the S13P family of ribosomal proteins. It is located in the cytoplasm. The gene product of the E. coli ortholog (ribosomal protein S13) is involved in the binding of fMet-tRNA, and thus, in the initiation of translation. This gene is an ortholog of mouse Ke3. As is typical for genes encoding ribosomal proteins, there are multiple processed pseudogenes of this gene dispersed through the genome. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

152 residues, UniProt reviewed canonical sequence.

>P62269|RPS18
     1  MSLVIPEKFQ HILRVLNTNI DGRRKIAFAI TAIKGVGRRY AHVVLRKADI DLTKRAGELT
    61  EDEVERVITI MQNPRQYKIP DWFLNRQKDV KDGKYSQVLA NGLDNKLRED LERLKKIRAH
   121  RGLRHFWGLR VRGQHTKTTG RRGRTVGVSK KK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against RPS18 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
0
Mean surface accessibility (rSASA)
0.38
Highest tissue expression
7,637 nTPM

Expression across tissuesHPA

Tissue

  • ovary: 7,637 nTPM
  • skin: 7,459 nTPM
  • pancreas: 6,373 nTPM
  • bone marrow: 5,719 nTPM
  • breast: 5,711 nTPM
  • esophagus: 5,231 nTPM

Single-cell type

  • esophageal suprabasal cells: 23,956 nCPM
  • decidual stromal cells: 23,140 nCPM
  • suprabasal keratinocytes: 21,293 nCPM
  • esophageal basal cells: 19,152 nCPM
  • extravillous trophoblasts: 18,014 nCPM
  • breast secretory cells: 17,196 nCPM

Immune cell

  • total PBMC: 9,425 nTPM
  • memory B-cell: 5,658 nTPM
  • naive CD4 T-cell: 4,985 nTPM
  • memory CD4 T-cell: 4,561 nTPM
  • naive B-cell: 4,536 nTPM
  • naive CD8 T-cell: 4,390 nTPM

Brain region

  • spinal cord: 703 nTPM
  • thalamus: 646 nTPM
  • white matter: 645 nTPM
  • medulla oblongata: 574 nTPM
  • basal ganglia: 539 nTPM
  • hypothalamus: 519 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)
0.26
gnomAD pLI
0.98
gnomAD missense Z
2.82
DepMap mean gene effect
-2.33
DepMap dependency class
pan

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 6% 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 RPS18 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 RPS18 as an antibody target. Whether an autoantibody or antibody against RPS18 could matter depends on whether native RPS18 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

RPS18 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 RPS18 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/RPS18. 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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