Seroatlas · Human Serome Atlas

PKNOX1

Homeobox protein PKNOX1

Also known as: PKNX1_HUMAN, PREP1

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

Protein identityUniProt · HPA

UniProt accession: P55347
Gene: PKNOX1
Ensembl: ENSG00000160199
Chromosome: 21
Canonical length: 436 aa
Protein class: Predicted intracellular proteins, Transcription factors
Subcellular location: Nucleoplasm

OverviewNCBI Gene

Enables sequence-specific double-stranded DNA binding activity. Predicted to be involved in angiogenesis. Predicted to act upstream of or within camera-type eye development; hemopoiesis; and positive regulation of transcription by RNA polymerase II. Located in cytosol and nucleus. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

436 residues, UniProt reviewed canonical sequence.

>P55347|PKNOX1
     1  MMATQTLSID SYQDGQQMQV VTELKTEQDP NCSEPDAEGV SPPPVESQTP MDVDKQAIYR
    61  HPLFPLLALL FEKCEQSTQG SEGTTSASFD VDIENFVRKQ EKEGKPFFCE DPETDNLMVK
   121  AIQVLRIHLL ELEKVNELCK DFCSRYIACL KTKMNSETLL SGEPGSPYSP VQSQQIQSAI
   181  TGTISPQGIV VPASALQQGN VAMATVAGGT VYQPVTVVTP QGQVVTQTLS PGTIRIQNSQ
   241  LQLQLNQDLS ILHQDDGSSK NKRGVLPKHA TNVMRSWLFQ HIGHPYPTED EKKQIAAQTN
   301  LTLLQVNNWF INARRRILQP MLDSSCSETP KTKKKTAQNR PVQRFWPDSI ASGVAQPPPS
   361  ELTMSEGAVV TITTPVNMNV DSLQSLSSDG ATLAVQQVMM AGQSEDESVD STEEDAGALA
   421  PAHISGLVLE NSDSLQ

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PKNOX1 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): 0.58
Highest tissue expression: 12 nTPM

Expression across tissuesHPA

Tissue

cerebellum: 12 nTPM
thyroid gland: 11 nTPM
ovary: 7.8 nTPM
testis: 7.7 nTPM
cervix: 7.2 nTPM
endometrium: 7.2 nTPM

Single-cell type

late primary spermatocytes: 192 nCPM
neutrophils: 192 nCPM
early spermatids: 135 nCPM
neutrophil progenitors: 106 nCPM
renal collecting duct principal cells: 79 nCPM
podocytes: 66 nCPM

Immune cell

neutrophil: 5.7 nTPM
MAIT T-cell: 4.1 nTPM
gdT-cell: 3.9 nTPM
naive CD4 T-cell: 3.3 nTPM
T-reg: 3.3 nTPM
memory CD8 T-cell: 3.2 nTPM

Brain region

cerebellum: 15 nTPM
spinal cord: 10 nTPM
white matter: 10 nTPM
hypothalamus: 9.8 nTPM
medulla oblongata: 9.4 nTPM
cerebral cortex: 9 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): 0.26
gnomAD pLI: 0.99
gnomAD missense Z: 1.48
DepMap mean gene effect: 0
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% 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 PKNOX1 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 PKNOX1 as an antibody target. Whether an autoantibody or antibody against PKNOX1 could matter depends on whether native PKNOX1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PKNOX1 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 PKNOX1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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