Disease relevance of Ptbp1

• Our data show that hypoxia may increase insulin mRNA levels by promoting the binding of PTB to the insulin mRNA 3'-UTR [1].

High impact information on Ptbp1

• We have used the yeast two-hybrid system to isolate Nova interacting proteins and identify an RNA binding protein that is closely related to the polypyrimidine tract-binding protein (PTB) [2].
• The ISS1 sequence is pyrimidine rich, and in vitro cross-linking studies demonstrate binding of polypyrimidine tract binding protein (PTB) to this element [3].
• Cotransfection of a PTB-1 expression vector with a minigene containing exon IIIb and the intronic splicing silencer element demonstrate PTB-mediated repression of exon IIIb splicing [3].
• An intronic splicing silencer causes skipping of the IIIb exon of fibroblast growth factor receptor 2 through involvement of polypyrimidine tract binding protein [3].
• We suggest that replacement of PTB by smPTB might be important in controlling some pre-mRNA alternative splicing events [4].

Chemical compound and disease context of Ptbp1

• Hypoxia may increase rat insulin mRNA levels by promoting binding of the polypyrimidine tract-binding protein (PTB) to the pyrimidine-rich insulin mRNA 3'-untranslated region [1].

Biological context of Ptbp1

• PYBP is highly homologous to a mouse nuclear protein, as well as to PTB, its human version, which interacts specifically with the pyrimidine tracts of introns [5].
• The amino acid sequences of tryptic peptides of the 42 kDa endonuclease show near-identity to polypyrimidine-tract binding protein (PTB) that is involved in the regulation of splicing of eukaryotic mRNA [6].
• This complex consists of two UCUU motifs in an intronic U-rich sequence (putative PTB (polypyrimidine tract binding) or T cell inhibitor of apoptosis-1 binding sites), an intronic 67-nucleotide enhancer that has similarities with the cardiac Troponin T MSE3 enhancer, and a potentially novel exonic splicing enhancer [7].
• A high affinity binding site for the polypyrimidine tract binding protein (PTB) is located in the 5'-untranslated region of the rat proteinase alpha1-inhibitor 3 variant I gene [8].
• Thus, our results suggest an involvement of mTOR in glucose-induced PTB/ins-PRS binding and insulin mRNA stability [9].

Anatomical context of Ptbp1

• We report the identification and characterization of a fourth rodent PTB paralog (smPTB) that is expressed at high levels in a number of smooth muscle tissues [4].
• A novel structure-specific endonuclease activity associated with polypyrimidine-tract binding (PTB) related protein from rat testis [6].
• In cell-free translation analysis, immunodepletion of PTB from rabbit reticulocyte lysate caused an increase in albumin translation [10].

Associations of Ptbp1 with chemical compounds

• Cloning and sequencing of PYBP, a pyrimidine-rich specific single strand DNA-binding protein [5].
• The glucose-induced PTB-binding was only inhibited by the mTOR inhibitor rapamycin [9].

Analytical, diagnostic and therapeutic context of Ptbp1

• By electrophoretic mobility shift assays (EMSA) we have shown that a GST (glutathione S-transferase) fusion of the rat polypyrimidine tract binding protein (PTB) has a high affinity for the pyrimidine-rich sense strand but not for the complementary sequence of the 5'-untranslated region of the alpha1-I3 variant I gene [8].

References