Seroatlas · Human Serome Atlas

SPATA33

Spermatogenesis-associated protein 33

Also known as: C16orf55, FLJ31606, SPT33_HUMAN

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

Protein identityUniProt · HPA

UniProt accession: Q96N06
Gene: SPATA33
Ensembl: ENSG00000167523
Chromosome: 16
Canonical length: 139 aa
Protein class: Predicted intracellular proteins
Subcellular location: Nucleoplasm,Vesicles

OverviewNCBI Gene

Predicted to be involved in mitophagy. Predicted to act upstream of or within fertilization; flagellated sperm motility; and protein localization. Predicted to be located in male germ cell nucleus and sperm mitochondrial sheath. Predicted to be active in cytoplasm and nucleus. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

139 residues, UniProt reviewed canonical sequence.

>Q96N06|SPATA33
     1  MVTHAAGART FCEEQKKGST YSVPKSKEKL MEKHSQEARQ ADRESEKPVD SLHPGAGTAK
    61  HPPPAASLEE KPDVKQKSSR KKVVVPQIII TRASNETLVS CSSSGSDQQR TIREPEDWGP
   121  YRRHRNPSTA DAYNSHLKE

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SPATA33 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): 0.73
Highest tissue expression: 87 nTPM

Expression across tissuesHPA

Tissue

testis: 87 nTPM
choroid plexus: 13 nTPM
fallopian tube: 12 nTPM
kidney: 11 nTPM
hypothalamus: 8.6 nTPM
cerebral cortex: 8.5 nTPM

Single-cell type

late spermatids: 5,815 nCPM
early spermatids: 1,889 nCPM
late primary spermatocytes: 1,102 nCPM
fallopian tube ciliated cells: 178 nCPM
respiratory ciliated cells: 138 nCPM
early primary spermatocytes: 119 nCPM

Immune cell

NK-cell: 3.1 nTPM
basophil: 2.5 nTPM
memory B-cell: 2.3 nTPM
MAIT T-cell: 2.2 nTPM
memory CD8 T-cell: 2.2 nTPM
eosinophil: 2.1 nTPM

Brain region

choroid plexus: 15 nTPM
cerebral cortex: 13 nTPM
hippocampal formation: 12 nTPM
midbrain: 12 nTPM
medulla oblongata: 11 nTPM
amygdala: 11 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): 1.93
gnomAD pLI: 0
gnomAD missense Z: -2.13
DepMap mean gene effect: -0.15
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

mitophagy

Cellular components

Protein domainsUniProt · Pfam · InterPro

Protein of unknown function DUF4609
Domain of unknown function (DUF4609)

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of SPATA33 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 SPATA33 as an antibody target. Whether an autoantibody or antibody against SPATA33 could matter depends on whether native SPATA33 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SPATA33 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 SPATA33 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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