Seroatlas · Human Serome Atlas

KRTAP21-2

Keratin-associated protein 21-2

Also known as: KAP21.2, KR212_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q3LI59
Gene
KRTAP21-2
Ensembl
ENSG00000187026
Chromosome
21
Canonical length
83 aa
Protein class
Predicted intracellular proteins

OverviewNCBI Gene

Predicted to be located in cytosol. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

83 residues, UniProt reviewed canonical sequence.

>Q3LI59|KRTAP21-2
     1  MCCNYYRNCC GGCGYGSGWS SGCGYGCGYG CGYGSGCRYG SGYGTGCGYG CGYGSGCGYG
    61  CGYSSSCCGY RPLCYRRCYS SCY

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against KRTAP21-2 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)
0.59
Highest tissue expression
1.5 nTPM

Expression across tissuesHPA

Tissue

  • testis: 1.5 nTPM
  • skin: 1.3 nTPM
  • salivary gland: 0.1 nTPM
  • adipose tissue: 0 nTPM
  • adrenal gland: 0 nTPM
  • amygdala: 0 nTPM

Single-cell type

  • late primary spermatocytes: 8.4 nCPM
  • early spermatids: 4.5 nCPM
  • late spermatids: 0.7 nCPM
  • basal keratinocytes: 0.3 nCPM
  • microglia: 0.2 nCPM
  • corticotrophs: 0.1 nCPM

Immune cell

  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM
  • MAIT T-cell: 0 nTPM

Brain region

  • cerebral cortex: 0.2 nTPM
  • hypothalamus: 0.2 nTPM
  • pons: 0.2 nTPM
  • amygdala: 0.1 nTPM
  • hippocampal formation: 0.1 nTPM
  • medulla oblongata: 0.1 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 missense Z
0.47
DepMap mean gene effect
-0.02
DepMap dependency class
selective

OntologyGO

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads KRTAP21-2 as an antibody target. Whether an autoantibody or antibody against KRTAP21-2 could matter depends on whether native KRTAP21-2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

KRTAP21-2 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 KRTAP21-2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/KRTAP21-2. 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...