@article{mbs:/content/journal/micro/10.1099/mic.0.25920-0, author = "Ruiz, Cristina and Escribano, Victoria and Morgado, Eulalia and Molina, María and Mazón, María J.", title = "Cell-type-dependent repression of yeast a-specific genes requires Itc1p, a subunit of the Isw2p–Itc1p chromatin remodelling complex", journal= "Microbiology", year = "2003", volume = "149", number = "2", pages = "341-351", doi = "https://doi.org/10.1099/mic.0.25920-0", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.25920-0", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "MAPKK(K), MAPK kinase (kinase)", keywords = "MAPK, mitogen-activated protein kinase", abstract = "In Saccharomyces cerevisiae MAT a haploid cells, the a-specific genes are expressed, whereas in the MATα haploid and MAT a/α diploid cell types their transcription is repressed. It is shown in this report that Itc1p, a component of the ATP-dependent Isw2p–Itc1p chromatin remodelling complex, is required for the repression of a-specific genes. It has previously been reported that disruption of the ITC1 gene leads, in MATα cells, to an aberrant cell morphology resembling the polarized mating projection of cells responding to pheromone. The activation of the pheromone signalling pathway in itc1 mutants of both mating types was examined and found to be constitutively active in MATα itc1 but not in MAT a itc1 cells. Furthermore, unlike the wild-type, MATα itc1 and MAT a/α itc1/itc1 cells secrete a-factor and express significant levels of other a-specific genes. The results indicate that the inappropriate a-factor production in a MATα context, due to the derepression of the a-specific genes, produces an autocrine signalling loop that leads to the aberrant morphology displayed by MATα itc1 cells. It is suggested that the Isw2p–Itc1p complex contributes to maintain the repressive chromatin structure described for the asg operator present in the promoters of a-specific genes.", }