MULTIPLEX SELECTION TECHNIQUE (MUST) - AN APPROACH TO CLONE TRANSCRIPTION FACTOR-BINDING SITES

We have used a multiplex selection approach to construct a library of DNA-protein interaction sites recognized by many of the DNA-binding pr oteins present in a cell type, An estimated minimum of two-thirds of t he binding sites present in a library prepared from activated Jurkat T cells represent authentic transcription factor binding sites, We used the library for isolation of ''optimal'' binding site probes that fac ilitated cloning of a factor and to identify binding activities induce d within 2 hr of activation of Jurkat cells. Since a large fraction of the oligonucleotides obtained appear to represent ''optimal'' binding sites for sequence-specific DNA-binding proteins, it is feasible to c onstruct a catalog of consensus binding sites for DNA-binding proteins in a given cell type, Qualitative and quantitative comparisons of the catalogs of binding site sequences from various cell types could prov ide valuable insights into the process of differentiation acting at th e level of transcriptional control.