Seroatlas · Human Serome Atlas

FAAP20

Fanconi anemia core complex-associated protein 20

Also known as: C1orf86, FAP20_HUMAN, FLJ31031

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

Protein identityUniProt · HPA

UniProt accession: Q6NZ36
Gene: FAAP20
Ensembl: ENSG00000162585
Chromosome: 1
Canonical length: 180 aa
Protein class: Predicted intracellular proteins
Subcellular location: Nucleoplasm,Nuclear bodies,Cell Junctions

OverviewNCBI Gene

Enables K63-linked polyubiquitin modification-dependent protein binding activity and ubiquitin-modified protein reader activity. Involved in interstrand cross-link repair and translesion synthesis. Located in cell junction; chromatin; and nuclear body. Part of Fanconi anaemia nuclear complex. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

180 residues, UniProt reviewed canonical sequence.

>Q6NZ36|FAAP20
     1  MEAARRPRLG LSRRRPRPAG GPSGGRPWFL LGGDERERLW AELLRTVSPE LILDHEVPSL
    61  PAFPGQEPRC GPEPTEVFTV GPKTFSWTPF PPDLWGPGRS YRLLHGAGGH LESPARSLPQ
   121  RPAPDPCRAP RVEQQPSVEG AAALRSCPMC QKEFAPRLTQ LDVDSHLAQC LAESTEDVTW

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against FAAP20 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): 0.61
Highest tissue expression: 74 nTPM

Expression across tissuesHPA

Tissue

pituitary gland: 74 nTPM
kidney: 62 nTPM
prostate: 59 nTPM
adrenal gland: 58 nTPM
amygdala: 54 nTPM
hippocampal formation: 54 nTPM

Single-cell type

late spermatids: 617 nCPM
decidual stromal cells: 235 nCPM
extravillous trophoblasts: 191 nCPM
hofbauer cells: 184 nCPM
late primary spermatocytes: 172 nCPM
migrating cytotrophoblasts: 151 nCPM

Immune cell

eosinophil: 64 nTPM
plasmacytoid DC: 43 nTPM
memory B-cell: 28 nTPM
naive B-cell: 26 nTPM
naive CD4 T-cell: 22 nTPM
neutrophil: 21 nTPM

Brain region

thalamus: 58 nTPM
medulla oblongata: 52 nTPM
cerebellum: 44 nTPM
choroid plexus: 43 nTPM
spinal cord: 43 nTPM
hypothalamus: 41 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): 0.75
gnomAD pLI: 0.53
DepMap mean gene effect: -0.29
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

FAAP20, zinc finger UBZ2-type
FAAP20, FANCA interaction domain
Fanconi anemia core complex-associated protein
Ubiquitin-binding zinc-finger
FAAP20 FANCA interaction domain

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of FAAP20 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 FAAP20 as an antibody target. Whether an autoantibody or antibody against FAAP20 could matter depends on whether native FAAP20 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

FAAP20 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 FAAP20 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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