Open AccessFunctional domains of the yeast transcription/replication factor MCM1.
Author(s) -
Chantal Christ,
Bik Kwoon Tye
Publication year - 1991
Publication title -
genes and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.136
H-Index - 438
eISSN - 1549-5477
pISSN - 0890-9369
DOI - 10.1101/gad.5.5.751
Subject(s) - biology , minichromosome maintenance , transcription factor , pre replication complex , microbiology and biotechnology , origin recognition complex , dna replication , control of chromosome duplication , gene , dna replication factor cdt1 , transcription (linguistics) , genetics , eukaryotic dna replication , linguistics , philosophy
MCM1 is an essential yeast DNA-binding protein that affects both minichromosome maintenance, in a manner suggesting that it has DNA replication initiation function, and gene expression. It activates alpha-specific genes together with MAT alpha 1, and represses a-specific genes together with MAT alpha 2. Alone, MCM1 can activate transcription. To determine whether different domains of the protein mediate these diverse functions, we constructed and analyzed several mcm1 mutants. The gene expression and minichromosome maintenance phenotypes of these mutants suggest that the role of MCM1 in DNA replication initiation may not involve transcriptional activation. However, both transcription and replication activities require only the 80-amino-acid fragment of MCM1 homologous to the DNA-binding domain of the serum response factor (SRF). This small fragment is also sufficient for cell viability and repression of a-specific genes. A polyacidic amino acid stretch immediately adjacent to the SRF homologous domain of MCM1 was found to be important for activation of alpha-specific genes in alpha cells. Mutants lacking the acidic stretch confer higher expression from an alpha-specific UAS in a cells in addition to lower expression in alpha cells, suggesting that negative regulation at this site occurs in a cells, in addition to the well-documented positive regulation in alpha cells.