Seroatlas · Human Serome Atlas

RPL21

Large ribosomal subunit protein eL21

Also known as: DKFZp686C06101, FLJ27458, L21, MGC104274, MGC104275, MGC71252, RL21_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
P46778
Gene
RPL21
Ensembl
ENSG00000122026
Chromosome
13
Canonical length
160 aa
Protein class
Disease related genes, Human disease related genes, Predicted intracellular proteins, Ribosomal proteins
Subcellular location
Nucleoli fibrillar center,Endoplasmic reticulum,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 60S subunit. The protein belongs to the L21E family of ribosomal proteins. It is located in the cytoplasm. 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

160 residues, UniProt reviewed canonical sequence.

>P46778|RPL21
     1  MTNTKGKRRG TRYMFSRPFR KHGVVPLATY MRIYKKGDIV DIKGMGTVQK GMPHKCYHGK
    61  TGRVYNVTQH AVGIVVNKQV KGKILAKRIN VRIEHIKHSK SRDSFLKRVK ENDQKKKEAK
   121  EKGTWVQLKR QPAPPREAHF VRTNGKEPEL LEPIPYEFMA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against RPL21 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)
0.46
Highest tissue expression
4,788 nTPM

Expression across tissuesHPA

Tissue

  • ovary: 4,788 nTPM
  • bone marrow: 3,900 nTPM
  • pancreas: 3,759 nTPM
  • lymph node: 3,342 nTPM
  • breast: 3,312 nTPM
  • tonsil: 3,093 nTPM

Single-cell type

  • epididymal basal cells: 7,381 nCPM
  • ovarian stromal cells: 7,069 nCPM
  • epididymal efferent duct absorptive cells: 7,051 nCPM
  • gastric chief cells: 6,782 nCPM
  • decidual stromal cells: 6,777 nCPM
  • esophageal suprabasal cells: 6,755 nCPM

Immune cell

  • total PBMC: 17,590 nTPM
  • naive CD4 T-cell: 11,091 nTPM
  • memory B-cell: 9,632 nTPM
  • naive CD8 T-cell: 9,263 nTPM
  • naive B-cell: 8,783 nTPM
  • MAIT T-cell: 8,324 nTPM

Brain region

  • hypothalamus: 467 nTPM
  • white matter: 429 nTPM
  • spinal cord: 399 nTPM
  • medulla oblongata: 399 nTPM
  • basal ganglia: 396 nTPM
  • thalamus: 393 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about RPL21.

Disease | AllUniProt

Conditions RPL21 is implicated in, by any mechanism.

Disease | GeneticClinVar

1 pathogenic / likely-pathogenic of 33 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Hypotrichosis 12

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)
0.46
gnomAD pLI
0.84
gnomAD missense Z
1.53
DepMap mean gene effect
-2.72
DepMap dependency class
pan

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% 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 RPL21 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 RPL21 as an antibody target. Whether an autoantibody or antibody against RPL21 could matter depends on whether native RPL21 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

RPL21 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 RPL21 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/RPL21. 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...