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.
As a first step towards understanding the mechanism underlying the differential gene expression of the two variants of the rat proteinase-inhibitor alpha1-inhibitor 3 (alpha1-I3) corresponding genomic clones were isolated. The 100% similarity between the sequence of one genomic clone and that of the alpha1-13 variant I cDNA strongly suggested that its 5'-sequence represented the upstream region of the corresponding gene. Several putative cis-regulatory elements were identified as well as a polypyrimidine tract located between the transcription start site of the alpha1-I3 variant I mRNA and the AUG codon. The polypyrimidine tract functions as a positive cis-element in a heterologous promoter. 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.
Sickinger
S
S
Department of Biological Sciences, Heriot-Watt University, Edinburgh, UK.
Schweizer
M
M
D020121:5' Untranslated Regions / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation; D014644:Genetic Variation; D005982:Glutathione Transferase / Q000235:genetics; D008969:Molecular Sequence Data; D038941:Polypyrimidine Tract-Binding Protein; D011401:Promoter Regions, Genetic; D016601:RNA-Binding Proteins / Q000378:metabolism*; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D014158:Transcription, Genetic; D000515:alpha 1-Antitrypsin / Q000737:chemistry / Q000235:genetics*
D020121:5' Untranslated Regions; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D000515:alpha 1-Antitrypsin; D038941:Polypyrimidine Tract-Binding Protein; D005982:Glutathione Transferase