Mcm1 is required to coordinate G2-specific transcription in Saccharomyces cerevisiae.
In the budding yeast Saccharomyces cerevisiae, MCM1 encodes an essential DNA-binding protein that regulates transcription of many genes in cooperation with different associated factors. With the help of a conditional expression system, we show that Mcm1 depletion has a distinct effect on cell cycle progression by preventing cells from undergoing mitosis. Genes that normally exhibit a G2-to-M-phase-specific expression pattern, such as CLB1, CLB2, CDC5, SWI5, and ACE2, remain uninduced in the absence of functional Mcm1. In vivo footprinting experiments show that Mcm1, in conjunction with an Mcm1-recruited factor, binds to the promoter regions of SWI5 and CLB2 at sites shown to be involved in cell cycle regulation. However, promoter occupation at these sites is cell cycle independent, and therefore the regulatory system seems to operate on constitutively bound Mcm1 complexes. A gene fusion that provides Mcm1 with a strong transcriptional activation domain causes transcription of SWI5, CLB1, CLB2, and CDC5 at inappropriate times of the cell cycle. Thus, Mcm1 and a cooperating, cell cycle-regulated activation partner are directly involved in the coordinated expression of multiple G2-regulated genes. The arrest phenotype of Mcm1-depleted cells is consistent with low levels of Clb1 and Clb2 kinase. However, constitutive CLB2 expression does not suppress the mitotic defect, and therefore other essential activities required for the G2-to-M transition must also depend on Mcm1 function.
Althoefer
H
H
Institute for Molecular Biology, Hannover Medical School, Germany.
Schleiffer
A
A
Wassmann
K
K
Nordheim
A
A
Ammerer
G
G
D001483:Base Sequence; D001665:Binding Sites; D018797:Cell Cycle Proteins; D016384:Consensus Sequence; D019926:Cyclin B; D016213:Cyclins / Q000502:physiology; D017931:DNA Primers / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000378:metabolism* / Q000502:physiology*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D016195:G2 Phase; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D017405:Herpes Simplex Virus Protein Vmw65 / Q000378:metabolism; D026341:Minichromosome Maintenance 1 Protein; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D011993:Recombinant Fusion Proteins; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic
C093749:CLB2 protein, S cerevisiae; D018797:Cell Cycle Proteins; D019926:Cyclin B; D016213:Cyclins; D017931:DNA Primers; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D017405:Herpes Simplex Virus Protein Vmw65; D026341:Minichromosome Maintenance 1 Protein; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C080218:SWI5 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors