PTBP1
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1QM9, 1SJQ, 1SJR, 2AD9, 2ADB, 2ADC, 2EVZ, 3ZZY, 3ZZZ
Identifiers
Aliases	PTBP1, HNRNP-I, HNRNPI, HNRPI, PTB, PTB-1, PTB-T, PTB2, PTB3, PTB4, pPTB, polypyrimidine tract binding protein 1
External IDs	OMIM: 600693; MGI: 97791; HomoloGene: 49188; GeneCards: PTBP1; OMA:PTBP1 - orthologs
Gene location (Human) Chr. Chromosome 19 (human)[1] Band 19p13.3 Start 797,075 bp[1] End 812,327 bp[1]
Gene location (Mouse) Chr. Chromosome 10 (mouse)[2] Band 10 C1|10 39.72 cM Start 79,690,261 bp[2] End 79,700,605 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in thymus nipple mucosa of pharynx stromal cell of endometrium human penis pancreatic ductal cell pylorus islet of Langerhans cecum ventricular zone Top expressed in tail of embryo genital tubercle zygote yolk sac ventricular zone lip embryo embryo morula blastocyst More reference expression data BioGPS More reference expression data
Gene ontology Molecular function pre-mRNA binding protein binding poly-pyrimidine tract binding nucleic acid binding RNA binding Cellular component nucleolus extracellular exosome membrane nucleus nucleoplasm Biological process mRNA splicing, via spliceosome mRNA processing negative regulation of mRNA splicing, via spliceosome regulation of alternative mRNA splicing, via spliceosome negative regulation of RNA splicing RNA splicing negative regulation of muscle cell differentiation fibroblast growth factor receptor signaling pathway IRES-dependent viral translational initiation RNA metabolic process positive regulation of protein dephosphorylation positive regulation of calcineurin-NFAT signaling cascade Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 5725 19205 Ensembl ENSG00000011304 ENSMUSG00000006498 UniProt P26599 P17225 RefSeq (mRNA) NM_002819 NM_031990 NM_031991 NM_175847 NM_001077363 NM_001283013 NM_008956 RefSeq (protein) NP_002810 NP_114367 NP_114368 n/a Location (UCSC) Chr 19: 0.8 – 0.81 Mb Chr 10: 79.69 – 79.7 Mb PubMed search [3] [4]
Wikidata
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Polypyrimidine tract-binding protein 1 is a protein that in humans is encoded by the PTBP1 gene.^[5][6][7]

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.^[7]

In brains of mammals, transcripts from the PTBP1 gene are missing one exon (exon 9) that is included in the brains of other vertebrates, as a result of alternative splicing. This contributes to the evolutionary difference between the nervous system of mammals and other vertebrates.^[8]

PTBP1 has been shown to interact with HNRPK,^[9] PCBP2,^[9] SFPQ^[10][11] and HNRNPL.^[9][12]

This gene is targeted by the microRNA miR-124. During neuronal differentiation, miR-124 reduces PTBP1 levels, leading to the accumulation of correctly spliced PTBP2 mRNA and a dramatic increase in PTBP2 protein.^[13]