Seroatlas · Human Serome Atlas

RPL18A

Large ribosomal subunit protein eL20

Also known as: L18A, RL18A_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q02543
Gene
RPL18A
Ensembl
ENSG00000105640
Chromosome
19
Canonical length
176 aa
Protein class
Plasma proteins, Predicted intracellular proteins, Ribosomal proteins
Subcellular location
Nucleoplasm,Nucleoli,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 member of the L18AE family of ribosomal proteins that is a component of the 60S subunit. The encoded protein may play a role in viral replication by interacting with the hepatitis C virus internal ribosome entry site (IRES). This gene is co-transcribed with the U68 snoRNA, located within the third intron. As is typical for genes encoding ribosomal proteins, there are multiple processed pseudogenes of this gene dispersed throughout the genome. [provided by RefSeq, Jul 2012]

Canonical amino-acid sequenceUniProt

176 residues, UniProt reviewed canonical sequence.

>Q02543|RPL18A
     1  MKASGTLREY KVVGRCLPTP KCHTPPLYRM RIFAPNHVVA KSRFWYFVSQ LKKMKKSSGE
    61  IVYCGQVFEK SPLRVKNFGI WLRYDSRSGT HNMYREYRDL TTAGAVTQCY RDMGARHRAR
   121  AHSIQIMKVE EIAASKCRRP AVKQFHDSKI KFPLPHRVLR RQHKPRFTTK RPNTFF

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against RPL18A 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)
0.36
Highest tissue expression
4,017 nTPM

Expression across tissuesHPA

Tissue

  • pancreas: 4,017 nTPM
  • ovary: 3,767 nTPM
  • skin: 3,674 nTPM
  • skeletal muscle: 2,625 nTPM
  • choroid plexus: 2,532 nTPM
  • bone marrow: 2,522 nTPM

Single-cell type

  • esophageal suprabasal cells: 9,701 nCPM
  • extravillous trophoblasts: 9,623 nCPM
  • decidual stromal cells: 9,050 nCPM
  • esophageal basal cells: 8,944 nCPM
  • suprabasal keratinocytes: 7,007 nCPM
  • migrating cytotrophoblasts: 6,846 nCPM

Immune cell

  • total PBMC: 21,258 nTPM
  • naive B-cell: 15,506 nTPM
  • memory B-cell: 15,057 nTPM
  • naive CD4 T-cell: 10,015 nTPM
  • MAIT T-cell: 8,694 nTPM
  • memory CD4 T-cell: 8,523 nTPM

Brain region

  • choroid plexus: 898 nTPM
  • spinal cord: 578 nTPM
  • medulla oblongata: 542 nTPM
  • thalamus: 541 nTPM
  • white matter: 530 nTPM
  • basal ganglia: 517 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)
0.24
gnomAD pLI
0.98
gnomAD missense Z
1.35
DepMap mean gene effect
-2.47
DepMap dependency class
pan

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% 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

  • Large ribosomal subunit protein eL20, eukaryota
  • Large ribosomal subunit protein eL20 domain
  • Large ribosomal subunit protein eL20
  • Ribosomal proteins 50S-L18Ae/60S-L20/60S-L18A

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of RPL18A 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 RPL18A as an antibody target. Whether an autoantibody or antibody against RPL18A could matter depends on whether native RPL18A is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

RPL18A 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 RPL18A as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/RPL18A. 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).

© 2026 · Seroatlas, Discover Oregon LLC · Terms of use

Loading the interactive Seroatlas protein explorer...