Seroatlas · Human Serome Atlas

PIF1

ATP-dependent DNA helicase PIF1

Also known as: C15orf20, FLJ22692, PIF1_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q9H611
Gene
PIF1
Ensembl
ENSG00000140451
Chromosome
15
Canonical length
641 aa
Protein class
Enzymes, Predicted intracellular proteins
Subcellular location
Nucleoplasm

OverviewNCBI Gene

This gene encodes a DNA-dependent adenosine triphosphate (ATP)-metabolizing enzyme that functions as a 5' to 3' DNA helicase. The encoded protein can resolve G-quadruplex structures and RNA-DNA hybrids at the ends of chromosomes. It also prevents telomere elongation by inhibiting the actions of telomerase. Alternative splicing and the use of alternative start codons results in multiple isoforms that are differentially localized to either the mitochondria or the nucleus. [provided by RefSeq, Nov 2013]

Canonical amino-acid sequenceUniProt

641 residues, UniProt reviewed canonical sequence.

>Q9H611|PIF1
     1  MLSGIEAAAG EYEDSELRCR VAVEELSPGG QPRRRQALRT AELSLGRNER RELMLRLQAP
    61  GPAGRPRCFP LRAARLFTRF AEAGRSTLRL PAHDTPGAGA VQLLLSDCPP DRLRRFLRTL
   121  RLKLAAAPGP GPASARAQLL GPRPRDFVTI SPVQPEERRL RAATRVPDTT LVKRPVEPQA
   181  GAEPSTEAPR WPLPVKRLSL PSTKPQLSEE QAAVLRAVLK GQSIFFTGSA GTGKSYLLKR
   241  ILGSLPPTGT VATASTGVAA CHIGGTTLHA FAGIGSGQAP LAQCVALAQR PGVRQGWLNC
   301  QRLVIDEISM VEADLFDKLE AVARAVRQQN KPFGGIQLII CGDFLQLPPV TKGSQPPRFC
   361  FQSKSWKRCV PVTLELTKVW RQADQTFISL LQAVRLGRCS DEVTRQLQAT ASHKVGRDGI
   421  VATRLCTHQD DVALTNERRL QELPGKVHRF EAMDSNPELA STLDAQCPVS QLLQLKLGAQ
   481  VMLVKNLSVS RGLVNGARGV VVGFEAEGRG LPQVRFLCGV TEVIHADRWT VQATGGQLLS
   541  RQQLPLQLAW AMSIHKSQGM TLDCVEISLG RVFASGQAYV ALSRARSLQG LRVLDFDPMA
   601  VRCDPRVLHF YATLRRGRSL SLESPDDDEA ASDQENMDPI L

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PIF1 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)
0.32
Highest tissue expression
4.6 nTPM

Expression across tissuesHPA

Tissue

  • spleen: 4.6 nTPM
  • lymph node: 4.3 nTPM
  • bone marrow: 3.6 nTPM
  • thymus: 3.3 nTPM
  • esophagus: 3 nTPM
  • tonsil: 3 nTPM

Single-cell type

  • early spermatids: 30 nCPM
  • monocyte progenitors: 21 nCPM
  • plasma cells: 20 nCPM
  • megakaryocyte progenitors: 13 nCPM
  • enteric transient amplifying cells: 13 nCPM
  • esophageal basal cells: 12 nCPM

Immune cell

  • T-reg: 0.9 nTPM
  • gdT-cell: 0.3 nTPM
  • memory CD8 T-cell: 0.2 nTPM
  • MAIT T-cell: 0.1 nTPM
  • memory B-cell: 0.1 nTPM
  • naive CD8 T-cell: 0.1 nTPM

Brain region

  • medulla oblongata: 1.6 nTPM
  • cerebral cortex: 1.4 nTPM
  • hypothalamus: 1.4 nTPM
  • pons: 1 nTPM
  • midbrain: 0.9 nTPM
  • spinal cord: 0.7 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)
1.33
gnomAD pLI
0
gnomAD missense Z
0.31
DepMap mean gene effect
-0.06
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 6% 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 PIF1 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 PIF1 as an antibody target. Whether an autoantibody or antibody against PIF1 could matter depends on whether native PIF1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PIF1 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 PIF1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/PIF1. 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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