Seroatlas · Human Serome Atlas

AP5S1

AP-5 complex subunit sigma-1

Also known as: AP5S1_HUMAN, C20orf29, FLJ11168

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

Protein identityUniProt · HPA

UniProt accession: Q9NUS5
Gene: AP5S1
Ensembl: ENSG00000125843
Chromosome: 20
Canonical length: 200 aa
Protein class: Predicted intracellular proteins, Predicted membrane proteins
Subcellular location: Nucleoplasm,Cytosol

OverviewNCBI Gene

Involved in double-strand break repair via homologous recombination and endosomal transport. Located in several cellular components, including late endosome; lysosome; and nucleoplasm. Part of AP-type membrane coat adaptor complex. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

200 residues, UniProt reviewed canonical sequence.

>Q9NUS5|AP5S1
     1  MVHAFLIHTL RAPNTEDTGL CRVLYSCVFG AEKSPDDPRP HGAERDRLLR KEQILAVARQ
    61  VESMCRLQQQ ASGRPPMDLQ PQSSDEQVPL HEAPRGAFRL AAENPFQEPR TVVWLGVLSL
   121  GFALVLDAHE NLLLAEGTLR LLTRLLLDHL RLLAPSTSLL LRADRIEGIL TRFLPHGQLL
   181  FLNDQFVQGL EKEFSAAWPR

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against AP5S1 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): 0.31
Highest tissue expression: 18 nTPM

Expression across tissuesHPA

Tissue

skeletal muscle: 18 nTPM
liver: 14 nTPM
adrenal gland: 11 nTPM
heart muscle: 11 nTPM
testis: 11 nTPM
kidney: 10 nTPM

Single-cell type

platelets: 54 nCPM
late primary spermatocytes: 29 nCPM
cytotrophoblasts: 23 nCPM
syncytiotrophoblasts: 21 nCPM
migrating cytotrophoblasts: 19 nCPM
hofbauer cells: 18 nCPM

Immune cell

intermediate monocyte: 12 nTPM
gdT-cell: 10 nTPM
myeloid DC: 9.9 nTPM
T-reg: 9.9 nTPM
memory CD4 T-cell: 8.5 nTPM
memory CD8 T-cell: 8.4 nTPM

Brain region

choroid plexus: 18 nTPM
basal ganglia: 16 nTPM
cerebral cortex: 16 nTPM
hippocampal formation: 16 nTPM
amygdala: 15 nTPM
medulla oblongata: 15 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): 1.79
gnomAD pLI: 0
gnomAD missense Z: -0.62
DepMap mean gene effect: -0.01
DepMap dependency class: none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 11% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Cellular components

Protein domainsUniProt · Pfam · InterPro

AP-5 complex subunit sigma-1
AP-5 complex subunit sigma-1

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of AP5S1 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 AP5S1 as an antibody target. Whether an autoantibody or antibody against AP5S1 could matter depends on whether native AP5S1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

AP5S1 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 AP5S1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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