Seroatlas · Human Serome Atlas

FEN1

Flap endonuclease 1

Also known as: FEN-1, FEN1_HUMAN, MF1, RAD2

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

Protein identityUniProt · HPA

UniProt accession
P39748
Gene
FEN1
Ensembl
ENSG00000168496
Chromosome
11
Canonical length
380 aa
Protein class
Cancer-related genes, Plasma proteins, Predicted intracellular proteins
Subcellular location
Nucleoplasm,Nucleoli

OverviewNCBI Gene

The protein encoded by this gene removes 5' overhanging flaps in DNA repair and processes the 5' ends of Okazaki fragments in lagging strand DNA synthesis. Direct physical interaction between this protein and AP endonuclease 1 during long-patch base excision repair provides coordinated loading of the proteins onto the substrate, thus passing the substrate from one enzyme to another. The protein is a member of the XPG/RAD2 endonuclease family and is one of ten proteins essential for cell-free DNA replication. DNA secondary structure can inhibit flap processing at certain trinucleotide repeats in a length-dependent manner by concealing the 5' end of the flap that is necessary for both binding and cleavage by the protein encoded by this gene. Therefore, secondary structure can deter the protective function of this protein, leading to site-specific trinucleotide expansions. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

380 residues, UniProt reviewed canonical sequence.

>P39748|FEN1
     1  MGIQGLAKLI ADVAPSAIRE NDIKSYFGRK VAIDASMSIY QFLIAVRQGG DVLQNEEGET
    61  TSHLMGMFYR TIRMMENGIK PVYVFDGKPP QLKSGELAKR SERRAEAEKQ LQQAQAAGAE
   121  QEVEKFTKRL VKVTKQHNDE CKHLLSLMGI PYLDAPSEAE ASCAALVKAG KVYAAATEDM
   181  DCLTFGSPVL MRHLTASEAK KLPIQEFHLS RILQELGLNQ EQFVDLCILL GSDYCESIRG
   241  IGPKRAVDLI QKHKSIEEIV RRLDPNKYPV PENWLHKEAH QLFLEPEVLD PESVELKWSE
   301  PNEEELIKFM CGEKQFSEER IRSGVKRLSK SRQGSTQGRL DDFFKVTGSL SSAKRKEPEP
   361  KGSTKKKAKT GAAGKFKRGK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against FEN1 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)
0.3
Highest tissue expression
43 nTPM

Expression across tissuesHPA

Tissue

  • thymus: 43 nTPM
  • bone marrow: 37 nTPM
  • tonsil: 35 nTPM
  • lymph node: 32 nTPM
  • appendix: 20 nTPM
  • testis: 20 nTPM

Single-cell type

  • oocytes: 4.6 nCPM
  • early primary spermatocytes: 3.8 nCPM
  • erythrocyte progenitors: 3.5 nCPM
  • late primary spermatocytes: 1.8 nCPM
  • megakaryocyte progenitors: 1.5 nCPM
  • early spermatids: 1.3 nCPM

Immune cell

  • T-reg: 25 nTPM
  • basophil: 25 nTPM
  • plasmacytoid DC: 25 nTPM
  • NK-cell: 20 nTPM
  • MAIT T-cell: 17 nTPM
  • gdT-cell: 16 nTPM

Brain region

  • cerebellum: 20 nTPM
  • pons: 20 nTPM
  • choroid plexus: 17 nTPM
  • thalamus: 16 nTPM
  • cerebral cortex: 15 nTPM
  • midbrain: 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)
1.28
gnomAD pLI
0
gnomAD missense Z
1.36
DepMap mean gene effect
-0.82
DepMap dependency class
common

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

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of FEN1 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 FEN1 as an antibody target. Whether an autoantibody or antibody against FEN1 could matter depends on whether native FEN1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

FEN1 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 FEN1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/FEN1. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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