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Pheromone-regulated genes required for yeast mating differentiation.

Erdman S, Lin L, Malczynski M, Snyder M - J. Cell Biol. (1998)

Bottom Line: Transposon insertion alleles corresponding to 20 genes that are novel or had not previously been known to be pheromone regulated were examined for effects on the mating process.Mutations in four novel genes, FIG1, FIG2, KAR5/ FIG3, and FIG4 were found to cause mating defects.Our results indicate that a variety of novel genes are expressed specifically during mating differentiation to mediate proper cell morphogenesis, cell fusion, and other steps of the mating process.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Yale University, New Haven, Connecticut 06520-8103, USA.

ABSTRACT
Yeast cells mate by an inducible pathway that involves agglutination, mating projection formation, cell fusion, and nuclear fusion. To obtain insight into the mating differentiation of Saccharomyces cerevisiae, we carried out a large-scale transposon tagging screen to identify genes whose expression is regulated by mating pheromone. 91,200 transformants containing random lacZ insertions were screened for beta-galactosidase (beta-gal) expression in the presence and absence of alpha factor, and 189 strains containing pheromone-regulated lacZ insertions were identified. Transposon insertion alleles corresponding to 20 genes that are novel or had not previously been known to be pheromone regulated were examined for effects on the mating process. Mutations in four novel genes, FIG1, FIG2, KAR5/ FIG3, and FIG4 were found to cause mating defects. Three of the proteins encoded by these genes, Fig1p, Fig2p, and Fig4p, are dispensible for cell polarization in uniform concentrations of mating pheromone, but are required for normal cell polarization in mating mixtures, conditions that involve cell-cell communication. Fig1p and Fig2p are also important for cell fusion and conjugation bridge shape, respectively. The fourth protein, Kar5p/Fig3p, is required for nuclear fusion. Fig1p and Fig2p are likely to act at the cell surface as Fig1:: beta-gal and Fig2::beta-gal fusion proteins localize to the periphery of mating cells. Fig4p is a member of a family of eukaryotic proteins that contain a domain homologous to the yeast Sac1p. Our results indicate that a variety of novel genes are expressed specifically during mating differentiation to mediate proper cell morphogenesis, cell fusion, and other steps of the mating process.

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Sequences similar  to the consensus Ste12p  binding site in the upstream  regions of the FIG1, FIG2,  KAR5/FIG3, and FIG4 genes.  Sites preceded by an asterisk  indicate they occur on the  opposite strand. Underlined  sequences represent exact  matches to the PRE consensus sequence.
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Figure 2: Sequences similar to the consensus Ste12p binding site in the upstream regions of the FIG1, FIG2, KAR5/FIG3, and FIG4 genes. Sites preceded by an asterisk indicate they occur on the opposite strand. Underlined sequences represent exact matches to the PRE consensus sequence.

Mentions: An upstream regulatory element termed the PRE has been identified as mediating the pheromone-induced transcription of a number of genes involved in the mating response (e.g., FUS2, CSH1, MFA2, STE6, STE2, BAR1, Ty elements and CIK1) (Van Arsdell et al., 1987). These sequences represent potential binding sites for Ste12p, the transcription factor that mediates pheromone-induced transcription, and are generally found upstream of pheromone-induced protein coding sequences (Kronstad et al., 1987; Errede and Ammerer, 1989; Page and Snyder, 1992). We searched the regions immediately upstream of the four novel FIG genes characterized in this study and found sequences matching the PRE consensus (Fig. 2). Since several of these genes are pheromone dependent for their expression yet contain only PRE sites that differ from the consensus, these results indicate that variant PRE sites are likely to be important for Ste12p-dependent regulation of some genes (e.g., FIG1 and FIG4, Fig. 2). An additional search for Mcm1p binding sites, which can be found near PRE sites of a subset of pheromone-induced genes such as FUS1 (Herskowitz et al., 1992), failed to identify sequences in the upstream regions of the FIG1-4 genes closely matching the consensus binding site.


Pheromone-regulated genes required for yeast mating differentiation.

Erdman S, Lin L, Malczynski M, Snyder M - J. Cell Biol. (1998)

Sequences similar  to the consensus Ste12p  binding site in the upstream  regions of the FIG1, FIG2,  KAR5/FIG3, and FIG4 genes.  Sites preceded by an asterisk  indicate they occur on the  opposite strand. Underlined  sequences represent exact  matches to the PRE consensus sequence.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2140177&req=5

Figure 2: Sequences similar to the consensus Ste12p binding site in the upstream regions of the FIG1, FIG2, KAR5/FIG3, and FIG4 genes. Sites preceded by an asterisk indicate they occur on the opposite strand. Underlined sequences represent exact matches to the PRE consensus sequence.
Mentions: An upstream regulatory element termed the PRE has been identified as mediating the pheromone-induced transcription of a number of genes involved in the mating response (e.g., FUS2, CSH1, MFA2, STE6, STE2, BAR1, Ty elements and CIK1) (Van Arsdell et al., 1987). These sequences represent potential binding sites for Ste12p, the transcription factor that mediates pheromone-induced transcription, and are generally found upstream of pheromone-induced protein coding sequences (Kronstad et al., 1987; Errede and Ammerer, 1989; Page and Snyder, 1992). We searched the regions immediately upstream of the four novel FIG genes characterized in this study and found sequences matching the PRE consensus (Fig. 2). Since several of these genes are pheromone dependent for their expression yet contain only PRE sites that differ from the consensus, these results indicate that variant PRE sites are likely to be important for Ste12p-dependent regulation of some genes (e.g., FIG1 and FIG4, Fig. 2). An additional search for Mcm1p binding sites, which can be found near PRE sites of a subset of pheromone-induced genes such as FUS1 (Herskowitz et al., 1992), failed to identify sequences in the upstream regions of the FIG1-4 genes closely matching the consensus binding site.

Bottom Line: Transposon insertion alleles corresponding to 20 genes that are novel or had not previously been known to be pheromone regulated were examined for effects on the mating process.Mutations in four novel genes, FIG1, FIG2, KAR5/ FIG3, and FIG4 were found to cause mating defects.Our results indicate that a variety of novel genes are expressed specifically during mating differentiation to mediate proper cell morphogenesis, cell fusion, and other steps of the mating process.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Yale University, New Haven, Connecticut 06520-8103, USA.

ABSTRACT
Yeast cells mate by an inducible pathway that involves agglutination, mating projection formation, cell fusion, and nuclear fusion. To obtain insight into the mating differentiation of Saccharomyces cerevisiae, we carried out a large-scale transposon tagging screen to identify genes whose expression is regulated by mating pheromone. 91,200 transformants containing random lacZ insertions were screened for beta-galactosidase (beta-gal) expression in the presence and absence of alpha factor, and 189 strains containing pheromone-regulated lacZ insertions were identified. Transposon insertion alleles corresponding to 20 genes that are novel or had not previously been known to be pheromone regulated were examined for effects on the mating process. Mutations in four novel genes, FIG1, FIG2, KAR5/ FIG3, and FIG4 were found to cause mating defects. Three of the proteins encoded by these genes, Fig1p, Fig2p, and Fig4p, are dispensible for cell polarization in uniform concentrations of mating pheromone, but are required for normal cell polarization in mating mixtures, conditions that involve cell-cell communication. Fig1p and Fig2p are also important for cell fusion and conjugation bridge shape, respectively. The fourth protein, Kar5p/Fig3p, is required for nuclear fusion. Fig1p and Fig2p are likely to act at the cell surface as Fig1:: beta-gal and Fig2::beta-gal fusion proteins localize to the periphery of mating cells. Fig4p is a member of a family of eukaryotic proteins that contain a domain homologous to the yeast Sac1p. Our results indicate that a variety of novel genes are expressed specifically during mating differentiation to mediate proper cell morphogenesis, cell fusion, and other steps of the mating process.

Show MeSH
Related in: MedlinePlus