Seroatlas · Human Serome Atlas

KPNB1

Importin subunit beta-1

Also known as: IMB1, IMB1_HUMAN, Impnb, IPO1, IPOB, MGC2155, MGC2156, MGC2157, NTF97

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

Protein identityUniProt · HPA

UniProt accession: Q14974
Gene: KPNB1
Ensembl: ENSG00000108424
Chromosome: 17
Canonical length: 876 aa
Protein class: Plasma proteins, Predicted intracellular proteins, Transporters
Subcellular location: Nucleoplasm,Nuclear membrane,Cytosol

OverviewNCBI Gene

Nucleocytoplasmic transport, a signal- and energy-dependent process, takes place through nuclear pore complexes embedded in the nuclear envelope. The import of proteins containing a nuclear localization signal (NLS) requires the NLS import receptor, a heterodimer of importin alpha and beta subunits also known as karyopherins. Importin alpha binds the NLS-containing cargo in the cytoplasm and importin beta docks the complex at the cytoplasmic side of the nuclear pore complex. In the presence of nucleoside triphosphates and the small GTP binding protein Ran, the complex moves into the nuclear pore complex and the importin subunits dissociate. Importin alpha enters the nucleoplasm with its passenger protein and importin beta remains at the pore. Interactions between importin beta and the FG repeats of nucleoporins are essential in translocation through the pore complex. The protein encoded by this gene is a member of the importin beta family. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Feb 2013]

Canonical amino-acid sequenceUniProt

876 residues, UniProt reviewed canonical sequence.

>Q14974|KPNB1
     1  MELITILEKT VSPDRLELEA AQKFLERAAV ENLPTFLVEL SRVLANPGNS QVARVAAGLQ
    61  IKNSLTSKDP DIKAQYQQRW LAIDANARRE VKNYVLQTLG TETYRPSSAS QCVAGIACAE
   121  IPVNQWPELI PQLVANVTNP NSTEHMKEST LEAIGYICQD IDPEQLQDKS NEILTAIIQG
   181  MRKEEPSNNV KLAATNALLN SLEFTKANFD KESERHFIMQ VVCEATQCPD TRVRVAALQN
   241  LVKIMSLYYQ YMETYMGPAL FAITIEAMKS DIDEVALQGI EFWSNVCDEE MDLAIEASEA
   301  AEQGRPPEHT SKFYAKGALQ YLVPILTQTL TKQDENDDDD DWNPCKAAGV CLMLLATCCE
   361  DDIVPHVLPF IKEHIKNPDW RYRDAAVMAF GCILEGPEPS QLKPLVIQAM PTLIELMKDP
   421  SVVVRDTAAW TVGRICELLP EAAINDVYLA PLLQCLIEGL SAEPRVASNV CWAFSSLAEA
   481  AYEAADVADD QEEPATYCLS SSFELIVQKL LETTDRPDGH QNNLRSSAYE SLMEIVKNSA
   541  KDCYPAVQKT TLVIMERLQQ VLQMESHIQS TSDRIQFNDL QSLLCATLQN VLRKVQHQDA
   601  LQISDVVMAS LLRMFQSTAG SGGVQEDALM AVSTLVEVLG GEFLKYMEAF KPFLGIGLKN
   661  YAEYQVCLAA VGLVGDLCRA LQSNIIPFCD EVMQLLLENL GNENVHRSVK PQILSVFGDI
   721  ALAIGGEFKK YLEVVLNTLQ QASQAQVDKS DYDMVDYLNE LRESCLEAYT GIVQGLKGDQ
   781  ENVHPDVMLV QPRVEFILSF IDHIAGDEDH TDGVVACAAG LIGDLCTAFG KDVLKLVEAR
   841  PMIHELLTEG RRSKTNKAKT LATWATKELR KLKNQA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against KPNB1 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): 0.23
Highest tissue expression: 109 nTPM

Expression across tissuesHPA

Tissue

thymus: 109 nTPM
tonsil: 102 nTPM
testis: 94 nTPM
tongue: 82 nTPM
lymph node: 76 nTPM
urinary bladder: 74 nTPM

Single-cell type

neutrophils: 523 nCPM
late primary spermatocytes: 373 nCPM
megakaryocyte progenitors: 328 nCPM
erythrocyte progenitors: 280 nCPM
early primary spermatocytes: 264 nCPM
monocyte progenitors: 264 nCPM

Immune cell

neutrophil: 12 nTPM
eosinophil: 6.1 nTPM
MAIT T-cell: 5.8 nTPM
memory CD8 T-cell: 5.2 nTPM
memory CD4 T-cell: 4.7 nTPM
naive CD4 T-cell: 4.5 nTPM

Brain region

white matter: 125 nTPM
midbrain: 111 nTPM
medulla oblongata: 108 nTPM
hypothalamus: 105 nTPM
pons: 105 nTPM
spinal cord: 104 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): 0.09
gnomAD pLI: 1
gnomAD missense Z: 5.93
DepMap mean gene effect: -2.03
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 KPNB1 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 KPNB1 as an antibody target. Whether an autoantibody or antibody against KPNB1 could matter depends on whether native KPNB1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

KPNB1 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 KPNB1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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