Seroatlas · Human Serome Atlas

PXT1

Peroxisomal testis-specific protein 1

Also known as: PXT1_HUMAN, STEPP

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

Protein identityUniProt · HPA

UniProt accession: Q8NFP0
Gene: PXT1
Ensembl: ENSG00000179165
Chromosome: 6
Canonical length: 134 aa
Protein class: Predicted intracellular proteins
Subcellular location: Vesicles

OverviewNCBI Gene

Predicted to be involved in spermatogenesis. Predicted to act upstream of or within positive regulation of apoptotic process. Predicted to be located in nucleus and peroxisome. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

134 residues, UniProt reviewed canonical sequence.

>Q8NFP0|PXT1
     1  MKKKHDGIVY ETKEVLNPSP KVTHCCKSLW LKYSFQKAYM TQLVSSQPVP AMSRNPDHNL
    61  LSQPKEHSIV QKHHQEEIIH KLAMQLRHIG DNIDHRMVRE DLQQDGRDAL DHFVFFFFRR
   121  VQVLLHFFWN NHLL

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PXT1 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: 2.2 nTPM

Expression across tissuesHPA

Tissue

testis: 2.2 nTPM
cerebellum: 0.3 nTPM
epididymis: 0.2 nTPM
skeletal muscle: 0.2 nTPM
adipose tissue: 0.1 nTPM
amygdala: 0.1 nTPM

Single-cell type

early primary spermatocytes: 21 nCPM
neutrophils: 19 nCPM
epicardial cells: 11 nCPM
hematopoietic stem cells: 7.8 nCPM
cdc: 7.3 nCPM
megakaryocyte-erythroid progenitors: 7.3 nCPM

Immune cell

neutrophil: 0.2 nTPM
eosinophil: 0.1 nTPM
memory B-cell: 0.1 nTPM
basophil: 0 nTPM
classical monocyte: 0 nTPM
gdT-cell: 0 nTPM

Brain region

cerebellum: 0.4 nTPM
cerebral cortex: 0.4 nTPM
amygdala: 0.3 nTPM
hippocampal formation: 0.3 nTPM
hypothalamus: 0.3 nTPM
white matter: 0.3 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): 1.94
gnomAD pLI: 0
gnomAD missense Z: -0.09
DepMap mean gene effect: 0.01
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

Cellular components

peroxisome

Protein domainsUniProt · Pfam · InterPro

Peroxisomal testis-specific protein 1
Peroxisomal testis-specific protein 1

KeywordsUniProt

Peroxisome

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads PXT1 as an antibody target. Whether an autoantibody or antibody against PXT1 could matter depends on whether native PXT1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PXT1 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 PXT1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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