Cell differentiation by interaction of two HMG-box proteins: Mat1-Mc activates M cell-specific genes in S.pombe by recruiting the ubiquitous transcription factor Ste11 to weak binding sites
Research output: Contribution to journal › Journal article › Research › peer-review
The Schizosaccharomyces pombe mfm1 gene is expressed in an M cell-specific fashion. This regulation requires two HMG-box proteins: the ubiquitous Ste11 transcription factor and the M cell-controlling protein Mat1-Mc. Here we report that the mfm1 promoter contains a single, weak Stell-binding site (a so-called TR-box) that can confer M-specificity on a heterologous promoter when present in eight copies. In vitro, both Mat1-Mc and Ste11 can bind this box with approximately the same affinity. The Mat1-Mc protein caused a dramatic increase in the DNA-binding of Ste11 to this box, under conditions where we could not detect Mat1-Mc in the resulting protein-DNA complex. When we changed a single base in the mfm1 TR-box, such that it resembled those boxes found in ubiquitously expressed genes, Ste11 binding was enhanced, and in vivo the mfm1 gene also became expressed in P cells where Mat1-Mc is absent. These findings suggest that M-specificity results from Mat1-Mc-mediated Ste11 binding to weak TR-boxes. We have also defined a novel motif (termed M-box), adjacent to the mfm1 TR-box, to which Mat1-Mc binds strongly. A DNA fragment containing both the TR- and the M-box allowed the formation of a complex containing both Ste11 and Mat1-Mc. A single copy of this fragment was sufficient to activate a heterologous promoter in an M-specific fashion, suggesting that these two boxes act in a synergistic manner.
Original language | English |
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Journal | E M B O Journal |
Volume | 16 |
Issue number | 13 |
Pages (from-to) | 4021-33 |
Number of pages | 13 |
ISSN | 0261-4189 |
DOIs | |
Publication status | Published - 1 Jul 1997 |
- Base Sequence, Binding Sites, Cell Differentiation, DNA, Fungal, Deoxyribonuclease I, Fungal Proteins, Gene Expression Regulation, Fungal, Genes, Fungal, Mitosis, Molecular Sequence Data, Mutagenesis, Site-Directed, Peptides, Promoter Regions, Genetic, Recombinant Fusion Proteins, Schizosaccharomyces, Schizosaccharomyces pombe Proteins, Transcription Factors
Research areas
ID: 33576951