High impact information on BAR1

• The MAT alpha 2 protein represses the transcription of a-cell-specific genes, including BAR1, in alpha and a/alpha diploid cells [1].
• In yeast alpha cells the a cell-specific genes STE6 and BAR1 are packaged as gene-sized chromatin domains of positioned nucleosomes [2].
• We report here the DNA sequence of BAR1, the structural gene for barrier activity [3].
• Other yeast genes with PREs, e.g., STE2 and BAR1, are more modestly inducible and have additional UAS elements contributing to the overall activity [4].
• Control of yeast cell type by the mating type locus. I. Identification and control of expression of the a-specific gene BAR1 [5].

Biological context of BAR1

• The amino acid sequence deduced from the gene shows extensive homology to a number of aspartyl proteases including the PEP4 and BAR1 gene products from S. cerevisiae [6].
• In contrast to the BAR1 gene product, the novel aspartyl protease (YAP3 for Yeast Aspartyl Protease 3) contains a C-terminal serine/threonine-rich sequence and potential transmembrane domain similar to those found in the KEX2 gene product [6].
• According to the published sequence of the CHS1 gene, this fragment contains four repeats of a TGAAACA consensus sequence previously identified in the alpha-factor-inducible BAR1 promoter [Kronstad, J. W., Holly, J. A. and MacKay, V. L. (1987) Cell 50, 369-377] [7].
• Forty-eight mRNAs were found to change significantly in translation state following release from alpha-factor arrest, including genes involved in pheromone response and cell cycle arrest such as BAR1, SST2, and FAR1 [8].
• 5. The properties of this activity have important implications concerning the role of the BAR1 gene product in recovery of mating-type a cells from cell division arrest by alpha-factor [9].

Associations of BAR1 with chemical compounds

• We report here that a positioned nucleosome in the BAR1 promoter is disrupted in cis by the insertion of diverse DNA sequences such as poly(dA) . poly(dT) and poly(dC-dG) . poly(dC-dG), leading to inappropriate partial derepression of BAR1 [10].

Other interactions of BAR1

• Analysis of axl1Delta in combination with other mutations that cause defects in morphogenesis or pheromone sensitivity (e.g. bar1, sst2, afr1) indicated that both phenotypes of ste2-T326 cells, supersensitivity to alpha-factor and the defect in forming pointed projections, contributed to the synergistic mating defect [11].

Analytical, diagnostic and therapeutic context of BAR1

• Complementation tests and linkage analysis showed that sst1 and bar1, a mutation which eliminates the ability of MATa cells to act as a "barrier" to the diffusion of alpha factor, were lesions in the same genes [12].

References