N-terminal arm of Mcm1 is required for transcription of a subset of genes involved in maintenance of the cell wall.
The yeast Mcm1 protein is a member of the MADS box family of transcription factors that interacts with several cofactors to differentially regulate genes involved in cell-type determination, mating, cell cycle control and arginine metabolism. Residues 18 to 96 of the protein, which form the core DNA-binding domain of Mcm1, are sufficient to carry out many Mcm1-dependent functions. However, deletion of residues 2 to 17, which form the nonessential N-terminal (NT) arm, confers a salt-sensitive phenotype, suggesting that the NT arm is required for the activation of salt response genes. We used a strategy that combined information from the mutational analysis of the Mcm1-binding site with microarray expression data under salt stress conditions to identify a new subset of Mcm1-regulated genes. Northern blot analysis showed that the transcript levels of several genes encoding associated with the cell wall, especially YGP1, decrease significantly upon deletion of the Mcm1 NT arm. Deletion of the Mcm1 NT arm results in a calcofluor white-sensitive phenotype, which is often associated with defects in transcription of cell wall genes. In addition, the deletion makes cells sensitive to CaCl2 and alkaline pH. We found that the defect caused by removal of the NT arm is not due to changes in Mcm1 protein level, stability, DNA-binding affinity, or DNA bending. This suggests that residues 2 to 17 of Mcm1 may be involved in recruiting a cofactor to the promoters of these genes to activate transcription.
Abraham
Deepu S
DS
Waksman Institute of Microbiology and Department of Molecular Biology and Biochemistry, Rutgers University, 190 Frelinghuysen Rd., Piscataway, NJ 08854-8020, USA.
Vershon
Andrew K
AK
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001665:Binding Sites; D002473:Cell Wall / Q000378:metabolism*; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism; D026161:MADS Domain Proteins; D026341:Minichromosome Maintenance 1 Protein; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D006023:Glycoproteins; D026161:MADS Domain Proteins; C498030:MCM1 protein, S cerevisiae; D026341:Minichromosome Maintenance 1 Protein; C095725:RLM1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C086475:YGP1 protein, S cerevisiae; D004247:DNA