Seroatlas · Human Serome Atlas

PTBP1

Polypyrimidine tract-binding protein 1

Also known as: HNRNP-I, HNRPI, pPTB, PTB, PTB-1, PTB2, PTB3, PTB4, PTBP1_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
P26599
Gene
PTBP1
Ensembl
ENSG00000011304
Chromosome
19
Canonical length
557 aa
Protein class
Plasma proteins, Predicted intracellular proteins
Subcellular location
Nucleoplasm

OverviewNCBI Gene

This gene belongs to the subfamily of ubiquitously expressed heterogeneous nuclear ribonucleoproteins (hnRNPs). The hnRNPs are RNA-binding proteins and they complex with heterogeneous nuclear RNA (hnRNA). These proteins are associated with pre-mRNAs in the nucleus and appear to influence pre-mRNA processing and other aspects of mRNA metabolism and transport. While all of the hnRNPs are present in the nucleus, some seem to shuttle between the nucleus and the cytoplasm. The hnRNP proteins have distinct nucleic acid binding properties. The protein encoded by this gene has four repeats of quasi-RNA recognition motif (RRM) domains that bind RNAs. This protein binds to the intronic polypyrimidine tracts that requires pre-mRNA splicing and acts via the protein degradation ubiquitin-proteasome pathway. It may also promote the binding of U2 snRNP to pre-mRNAs. This protein is localized in the nucleoplasm and it is also detected in the perinucleolar structure. Alternatively spliced transcript variants encoding different isoforms have been described. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

557 residues, UniProt reviewed canonical sequence.

>P26599|PTBP1
     1  MDGIVPDIAV GTKRGSDELF STCVTNGPFI MSSNSASAAN GNDSKKFKGD SRSAGVPSRV
    61  IHIRKLPIDV TEGEVISLGL PFGKVTNLLM LKGKNQAFIE MNTEEAANTM VNYYTSVTPV
   121  LRGQPIYIQF SNHKELKTDS SPNQARAQAA LQAVNSVQSG NLALAASAAA VDAGMAMAGQ
   181  SPVLRIIVEN LFYPVTLDVL HQIFSKFGTV LKIITFTKNN QFQALLQYAD PVSAQHAKLS
   241  LDGQNIYNAC CTLRIDFSKL TSLNVKYNND KSRDYTRPDL PSGDSQPSLD QTMAAAFGAP
   301  GIISASPYAG AGFPPTFAIP QAAGLSVPNV HGALAPLAIP SAAAAAAAAG RIAIPGLAGA
   361  GNSVLLVSNL NPERVTPQSL FILFGVYGDV QRVKILFNKK ENALVQMADG NQAQLAMSHL
   421  NGHKLHGKPI RITLSKHQNV QLPREGQEDQ GLTKDYGNSP LHRFKKPGSK NFQNIFPPSA
   481  TLHLSNIPPS VSEEDLKVLF SSNGGVVKGF KFFQKDRKMA LIQMGSVEEA VQALIDLHNH
   541  DLGENHHLRV SFSKSTI

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PTBP1 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)
0.41
Highest tissue expression
130 nTPM

Expression across tissuesHPA

Tissue

  • bone marrow: 130 nTPM
  • esophagus: 124 nTPM
  • skin: 112 nTPM
  • liver: 112 nTPM
  • spleen: 108 nTPM
  • appendix: 99 nTPM

Single-cell type

  • extravillous trophoblasts: 204 nCPM
  • monocyte progenitors: 185 nCPM
  • migrating cytotrophoblasts: 173 nCPM
  • erythrocyte progenitors: 167 nCPM
  • megakaryocyte progenitors: 164 nCPM
  • megakaryocytes: 161 nCPM

Immune cell

  • intermediate monocyte: 39 nTPM
  • total PBMC: 38 nTPM
  • non-classical monocyte: 37 nTPM
  • myeloid DC: 36 nTPM
  • NK-cell: 34 nTPM
  • classical monocyte: 33 nTPM

Brain region

  • choroid plexus: 81 nTPM
  • medulla oblongata: 54 nTPM
  • thalamus: 50 nTPM
  • cerebral cortex: 50 nTPM
  • midbrain: 49 nTPM
  • pons: 49 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about PTBP1.

Disease | GeneticClinVar

8 pathogenic / likely-pathogenic of 126 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

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)
0.18
gnomAD pLI
1
gnomAD missense Z
1.65
DepMap mean gene effect
-0.37
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

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of PTBP1 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 PTBP1 as an antibody target. Whether an autoantibody or antibody against PTBP1 could matter depends on whether native PTBP1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PTBP1 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 PTBP1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/PTBP1. 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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