Author:
Roux E,Strubin M,Hagenbüchle O,Wellauer P K
Abstract
The cognate sequence of transcription factor PTF1, which plays a key role in pancreas-specific gene expression, has a bipartite organization. Two separate DNA domains, the A and the B boxes, are required for efficient binding of the factor. The structure of PTF1 was elucidated by cross-linking purified PTF1 to DNA templates that had been differentially substituted with azido-deoxyuridine (N3.dU). This site-directed UV cross-linking shows that PTF1 contains two DNA-binding proteins, distinct in size and sensitivity to Staphylococcus aureus V8 protease. A 64-kD protein is cross-linked with DNA containing N3.dU substitutions in the A box, and a 48-kD protein is cross-linked with DNA containing N3.dU substitutions in the B box. Both proteins bind simultaneously to the same DNA molecule. The data indicate that PTF1 is a heteromeric oligomer and that its cell-specific DNA-binding potential is the result of a concerted activity of two DNA-binding subunits.
Publisher
Cold Spring Harbor Laboratory
Subject
Developmental Biology,Genetics
Reference18 articles.
1. Cell-specific enhancers in the rat exocrine pancreas.
2. Factors involved in control of tissue-specific expression of albumin gene
3. A single polypeptide possesses the binding and transcription activities of the adenovirus major late transcription factor.;Mol Cell. Biol.,1986
4. A yeast and a human CCAAT-binding protein have heterologous subunits that are functionally interchangeable
5. Identification of a cell-specific DNA-binding activity that interacts with a transcriptional activator of genes expressed in the acinar pancreas.;Mol. Cell. Biol.,1989