Seroatlas · Human Serome Atlas

KPNA2

Importin subunit alpha-1

Also known as: IMA1_HUMAN, IPOA1, PTAC58, QIP2, RCH1, SRP1alpha

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

Protein identityUniProt · HPA

UniProt accession
P52292
Gene
KPNA2
Ensembl
ENSG00000182481
Chromosome
17
Canonical length
529 aa
Protein class
Plasma proteins, Predicted intracellular proteins, Transporters
Subcellular location
Nucleoplasm,Cytosol

OverviewNCBI Gene

The import of proteins into the nucleus is a process that involves at least 2 steps. The first is an energy-independent docking of the protein to the nuclear envelope and the second is an energy-dependent translocation through the nuclear pore complex. Imported proteins require a nuclear localization sequence (NLS) which generally consists of a short region of basic amino acids or 2 such regions spaced about 10 amino acids apart. Proteins involved in the first step of nuclear import have been identified in different systems. These include the Xenopus protein importin and its yeast homolog, SRP1 (a suppressor of certain temperature-sensitive mutations of RNA polymerase I in Saccharomyces cerevisiae), which bind to the NLS. KPNA2 protein interacts with the NLSs of DNA helicase Q1 and SV40 T antigen and may be involved in the nuclear transport of proteins. KPNA2 also may play a role in V(D)J recombination. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2016]

Canonical amino-acid sequenceUniProt

529 residues, UniProt reviewed canonical sequence.

>P52292|KPNA2
     1  MSTNENANTP AARLHRFKNK GKDSTEMRRR RIEVNVELRK AKKDDQMLKR RNVSSFPDDA
    61  TSPLQENRNN QGTVNWSVDD IVKGINSSNV ENQLQATQAA RKLLSREKQP PIDNIIRAGL
   121  IPKFVSFLGR TDCSPIQFES AWALTNIASG TSEQTKAVVD GGAIPAFISL LASPHAHISE
   181  QAVWALGNIA GDGSVFRDLV IKYGAVDPLL ALLAVPDMSS LACGYLRNLT WTLSNLCRNK
   241  NPAPPIDAVE QILPTLVRLL HHDDPEVLAD TCWAISYLTD GPNERIGMVV KTGVVPQLVK
   301  LLGASELPIV TPALRAIGNI VTGTDEQTQV VIDAGALAVF PSLLTNPKTN IQKEATWTMS
   361  NITAGRQDQI QQVVNHGLVP FLVSVLSKAD FKTQKEAVWA VTNYTSGGTV EQIVYLVHCG
   421  IIEPLMNLLT AKDTKIILVI LDAISNIFQA AEKLGETEKL SIMIEECGGL DKIEALQNHE
   481  NESVYKASLS LIEKYFSVEE EEDQNVVPET TSEGYTFQVQ DGAPGTFNF

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against KPNA2 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
Other membrane
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.28
Highest tissue expression
196 nTPM

Expression across tissuesHPA

Tissue

  • testis: 196 nTPM
  • tonsil: 98 nTPM
  • bone marrow: 94 nTPM
  • thymus: 88 nTPM
  • lymph node: 67 nTPM
  • appendix: 43 nTPM

Single-cell type

  • late primary spermatocytes: 1,344 nCPM
  • early spermatids: 806 nCPM
  • oocytes: 534 nCPM
  • extravillous trophoblasts: 358 nCPM
  • late spermatids: 324 nCPM
  • migrating cytotrophoblasts: 219 nCPM

Immune cell

  • myeloid DC: 57 nTPM
  • memory B-cell: 48 nTPM
  • intermediate monocyte: 48 nTPM
  • NK-cell: 45 nTPM
  • plasmacytoid DC: 44 nTPM
  • naive B-cell: 42 nTPM

Brain region

  • hypothalamus: 26 nTPM
  • white matter: 23 nTPM
  • pons: 20 nTPM
  • cerebral cortex: 20 nTPM
  • hippocampal formation: 17 nTPM
  • spinal cord: 17 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)
0.44
gnomAD pLI
0.54
gnomAD missense Z
0.37
DepMap mean gene effect
-0.37
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 8% 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 KPNA2 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 KPNA2 as an antibody target. Whether an autoantibody or antibody against KPNA2 could matter depends on whether native KPNA2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

KPNA2 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 KPNA2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/KPNA2. 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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