Identification of a cell-specific DNA-binding activity that interacts with a transcriptional activator of genes expressed in the acinar pancreas.
Footprint analysis of the 5'-flanking regions of the alpha-amylase 2, elastase 2, and trypsina genes, which are expressed in the acinar pancreas, showed multiple sites of protein-DNA interaction for each gene. Competition experiments demonstrated that a region from each 5'-flanking region interacted with the same cell-specific DNA-binding activity. We show by in vitro binding assays that this DNA-binding activity also recognizes a sequence within the 5'-flanking regions of elastase 1, chymotrypsinogen B, carboxypeptidase A, and trypsind genes. Methylation interference and protection studies showed that the DNA-binding activity recognized a bipartite motif, the subelements of which were separated by integral helical turns of DNA. The alpha-amylase 2 cognate sequence was found to enhance in vivo transcription of its own promoter in a cell-specific manner, which identified the DNA-binding activity as a transcription factor (PTF 1). The observation that PTF 1 bound to DNA sequences that have been defined as transcriptional enhancers by others suggests that this factor is involved in the coordinate expression of genes transcribed in the acinar pancreas.
Cockell
M
M
Swiss Institute for Experimental Cancer Research, Epalinges, Switzerland.
Stevenson
B J
BJ
Strubin
M
M
Hagenbüchle
O
O
Wellauer
P K
PK
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D003850:Deoxyribonuclease I; D008745:Methylation; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000235:genetics; D010179:Pancreas / Q000201:enzymology / Q000378:metabolism*; D010196:Pancreatic Elastase / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D014157:Transcription Factors / Q000378:metabolism*; D014162:Transfection; D014357:Trypsin / Q000235:genetics; D000516:alpha-Amylases / Q000235:genetics
D004268:DNA-Binding Proteins; D009841:Oligonucleotides; D012333:RNA, Messenger; D014157:Transcription Factors; D004247:DNA; D003850:Deoxyribonuclease I; D000516:alpha-Amylases; D010196:Pancreatic Elastase; D014357:Trypsin