A new role for MCM1 in yeast: cell cycle regulation of SW15 transcription.
In the yeast Saccharomyces cerevisiae cell cycle-regulated SW15 transcription is essential for ensuring that mother and not daughter cells switch mating type. We have identified a 55-bp promoter sequence that appears to be responsible for restricting transcription to the late S, G2, and M phases of the cell cycle. Two proteins, MCM1, a transcription factor described previously, and SFF (SWI five factor, a newly identified factor) bind this sequence in vitro. MCM1 binds the DNA tightly on its own, but SFF will only bind as part of a ternary complex with MCM1. We observe a strong correlation between the ability of mutated SWI5 promoter sequences to form a ternary MCM1-SFF-containing complex in vitro and to activate transcription in vivo, which suggests that efficient transcription requires that both proteins bind DNA. Through its interactions with cell type-specific coactivators and corepressors, MCM1 controls cell type-specific expression of pheromone and receptor genes. By analogy, we propose that SFF enables MCM1 to function as a part of a cell cycle-regulated transcription complex.
Lydall
D
D
Research Institute of Molecular Pathology (IMP), University of Vienna, Austria.
Ammerer
G
G
Nasmyth
K
K
D001482:Base Composition; D001483:Base Sequence; D002453:Cell Cycle; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D026341:Minichromosome Maintenance 1 Protein; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012331:RNA, Fungal / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic
D005656:Fungal Proteins; D026341:Minichromosome Maintenance 1 Protein; D012331:RNA, Fungal; D014157:Transcription Factors