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Oya K, Matsuura A. Haploinsufficiency of the sex-determining genes at MATα restricts genome expansion in Saccharomyces cerevisiae. iScience 2022; 25:104783. [PMID: 35982788 PMCID: PMC9379577 DOI: 10.1016/j.isci.2022.104783] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 05/18/2022] [Accepted: 07/13/2022] [Indexed: 11/19/2022] Open
Affiliation(s)
- Kazumasa Oya
- Department of Biology, Graduate School of Science and Engineering, Chiba University, 1-33 Yayoi-chou, Inage-ku, Chiba 263-8522, Japan
| | - Akira Matsuura
- Department of Biology, Graduate School of Science, Chiba University, 1-33 Yayoi-chou, Inage-ku, Chiba 263-8522, Japan
- Corresponding author
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2
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Anders A, Colin R, Banderas A, Sourjik V. Asymmetric mating behavior of isogamous budding yeast. SCIENCE ADVANCES 2021; 7:7/24/eabf8404. [PMID: 34117059 PMCID: PMC8195471 DOI: 10.1126/sciadv.abf8404] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 04/28/2021] [Indexed: 05/12/2023]
Abstract
Anisogamy, the size difference between small male and large female gametes, is known to enable selection for sexual dimorphism and behavioral differences between sexes. Nevertheless, even isogamous species exhibit molecular asymmetries between mating types, which are known to ensure their self-incompatibility. Here, we show that different properties of the pheromones secreted by the MATa and MATα mating types of budding yeast lead to asymmetry in their behavioral responses during mating in mixed haploid populations, which resemble behavioral asymmetries between gametes in anisogamous organisms. MATa behaves as a random searcher that is stimulated in proportion to the fraction of MATα partner cells within the population, whereas MATα behaves as a short-range directional distance sensor. Mathematical modeling suggests that the observed asymmetric responses can enhance efficiency of mating and might thus provide a selective advantage. Our results demonstrate that the emergence of asymmetric mating behavior did not require anisogamy-based sexual selection.
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Affiliation(s)
- Alexander Anders
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- LOEWE Research Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Remy Colin
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- LOEWE Research Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Alvaro Banderas
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
- Laboratoire Physico Chimie Curie, CNRS UMR168, Institut Curie, Paris, France
| | - Victor Sourjik
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
- LOEWE Research Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
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3
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Heistinger L, Moser J, Tatto NE, Valli M, Gasser B, Mattanovich D. Identification and characterization of the Komagataella phaffii mating pheromone genes. FEMS Yeast Res 2018; 18:4987207. [PMID: 29718186 PMCID: PMC5993090 DOI: 10.1093/femsyr/foy051] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 04/24/2018] [Indexed: 12/30/2022] Open
Abstract
The methylotrophic yeast Komagataella phaffii (Pichia pastoris) is a haploid yeast that is able to form diploid cells by mating once nitrogen becomes limiting. Activation of the mating response requires the secretion of a- and α-factor pheromones, which bind to G-protein coupled receptors on cells of opposite mating type. In K. phaffii, the genes coding for the α-factor (MFα), the pheromone surface receptors and the conserved a-factor biogenesis pathway have been annotated previously. Initial homology-based search failed to identify potential a-factor genes (MFA). By using transcriptome data of heterothallic strains under mating conditions, we found two K. phaffiia-factor genes. Deletion of both MFA genes prevented mating of a-type cells. MFA single mutants were still able to mate and activate the mating response pathway in α-type cells. A reporter assay was used to confirm the biological activity of synthetic a- and α-factor peptides. The identification of the a-factor genes enabled the first characterization of the role and regulation of the mating pheromone genes and the response of K. phaffii to synthetic pheromones and will help to gain a better understanding of the mating behavior of K. phaffii.
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Affiliation(s)
- Lina Heistinger
- Christian Doppler Laboratory for Innovative Immunotherapeutics at Department of Biotechnology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Josef Moser
- Austrian Centre of Industrial Biotechnology (ACIB), Muthgasse 11, 1190 Vienna, Austria
- School of Bioengineering, University of Applied Sciences FH-Campus, Muthgasse 11, 1190 Vienna, Austria
| | - Nadine E Tatto
- Austrian Centre of Industrial Biotechnology (ACIB), Muthgasse 11, 1190 Vienna, Austria
- Department of Biotechnology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Minoska Valli
- Austrian Centre of Industrial Biotechnology (ACIB), Muthgasse 11, 1190 Vienna, Austria
- Department of Biotechnology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Brigitte Gasser
- Austrian Centre of Industrial Biotechnology (ACIB), Muthgasse 11, 1190 Vienna, Austria
- Department of Biotechnology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Diethard Mattanovich
- Austrian Centre of Industrial Biotechnology (ACIB), Muthgasse 11, 1190 Vienna, Austria
- Department of Biotechnology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
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4
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Banderas A, Koltai M, Anders A, Sourjik V. Sensory input attenuation allows predictive sexual response in yeast. Nat Commun 2016; 7:12590. [PMID: 27557894 PMCID: PMC5007329 DOI: 10.1038/ncomms12590] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 07/14/2016] [Indexed: 12/22/2022] Open
Abstract
Animals are known to adjust their sexual behaviour depending on mate competition. Here we report similar regulation for mating behaviour in a sexual unicellular eukaryote, the budding yeast Saccharomyces cerevisiae. We demonstrate that pheromone-based communication between the two mating types, coupled to input attenuation by recipient cells, enables yeast to robustly monitor relative mate abundance (sex ratio) within a mixed population and to adjust their commitment to sexual reproduction in proportion to their estimated chances of successful mating. The mechanism of sex-ratio sensing relies on the diffusible peptidase Bar1, which is known to degrade the pheromone signal produced by mating partners. We further show that such a response to sexual competition within a population can optimize the fitness trade-off between the costs and benefits of mating response induction. Our study thus provides an adaptive explanation for the known molecular mechanism of pheromone degradation in yeast. Cells of the yeast Saccharomyces cerevisiae can mate with other cells of opposite mating type. Here, the authors show that the combination of a pheromone and a pheromone-degrading enzyme allows yeast cells to monitor relative mate abundance within a population and adjust their commitment to sexual reproduction.
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Affiliation(s)
- Alvaro Banderas
- Max Planck Institute for Terrestrial Microbiology &LOEWE Research Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch-Str. 16, D-35037 Marburg, Germany.,Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Mihaly Koltai
- Max Planck Institute for Terrestrial Microbiology &LOEWE Research Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch-Str. 16, D-35037 Marburg, Germany
| | - Alexander Anders
- Max Planck Institute for Terrestrial Microbiology &LOEWE Research Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch-Str. 16, D-35037 Marburg, Germany
| | - Victor Sourjik
- Max Planck Institute for Terrestrial Microbiology &LOEWE Research Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch-Str. 16, D-35037 Marburg, Germany
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5
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Tao L, Cao C, Liang W, Guan G, Zhang Q, Nobile CJ, Huang G. White cells facilitate opposite- and same-sex mating of opaque cells in Candida albicans. PLoS Genet 2014; 10:e1004737. [PMID: 25329547 PMCID: PMC4199524 DOI: 10.1371/journal.pgen.1004737] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 09/08/2014] [Indexed: 11/19/2022] Open
Abstract
Modes of sexual reproduction in eukaryotic organisms are extremely diverse. The human fungal pathogen Candida albicans undergoes a phenotypic switch from the white to the opaque phase in order to become mating-competent. In this study, we report that functionally- and morphologically-differentiated white and opaque cells show a coordinated behavior during mating. Although white cells are mating-incompetent, they can produce sexual pheromones when treated with pheromones of the opposite mating type or by physically interacting with opaque cells of the opposite mating type. In a co-culture system, pheromones released by white cells induce opaque cells to form mating projections, and facilitate both opposite- and same-sex mating of opaque cells. Deletion of genes encoding the pheromone precursor proteins and inactivation of the pheromone response signaling pathway (Ste2-MAPK-Cph1) impair the promoting role of white cells (MTLa) in the sexual mating of opaque cells. White and opaque cells communicate via a paracrine pheromone signaling system, creating an environment conducive to sexual mating. This coordination between the two different cell types may be a trade-off strategy between sexual and asexual lifestyles in C. albicans. In eukaryotic organisms, cells often undergo differentiation into distinct cell types in order to fulfill specialized roles. To achieve a certain function, different cell types may behave coordinately to complete a task that they may otherwise be incapable of completing independently. The human fungal pathogen Candida albicans can exist as two functionally and morphologically distinct cell types: white and opaque. The white cell type is thought to be the default state and may be the majority cell population in nature. However, only the minority opaque cells are mating-competent. In this study, we report that white and opaque cells show a coordinated behavior in the process of mating. When in the presence of opaque cells with an opposite mating type, white cells release sexual pheromones, and thus create an environment conducive for both opposite- and same-sex mating of opaque cells. The two cell types communicate via a paracrine pheromone signaling system. We propose that this communal coordination between white and opaque cells may not only support the fungus to be a successful commensal and pathogen in the host, but may also increase the fitness of the fungus during evolution over time.
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Affiliation(s)
- Li Tao
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Chengjun Cao
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Weihong Liang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Guobo Guan
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Qiuyu Zhang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Clarissa J. Nobile
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, Merced, California, United States of America
| | - Guanghua Huang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- * E-mail:
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6
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A super-assembly of Whi3 encodes memory of deceptive encounters by single cells during yeast courtship. Cell 2014; 155:1244-57. [PMID: 24315096 DOI: 10.1016/j.cell.2013.10.046] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 08/02/2013] [Accepted: 10/25/2013] [Indexed: 01/15/2023]
Abstract
Cellular behavior is frequently influenced by the cell's history, indicating that single cells may memorize past events. We report that budding yeast permanently escape pheromone-induced cell-cycle arrest when experiencing a deceptive mating attempt, i.e., not reaching their putative partner within reasonable time. This acquired behavior depends on super-assembly and inactivation of the G1/S inhibitor Whi3, which liberates the G1 cyclin Cln3 from translational inhibition. Super-assembly of Whi3 is a slow response to pheromone, driven by polyQ and polyN domains, counteracted by Hsp70, and stable over generations. Unlike prion aggregates, Whi3 super-assemblies are not inherited mitotically but segregate to the mother cell. We propose that such polyQ- and polyN-based elements, termed here mnemons, act as cellular memory devices to encode previous environmental conditions.
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7
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Biogenesis of the Saccharomyces cerevisiae pheromone a-factor, from yeast mating to human disease. Microbiol Mol Biol Rev 2013; 76:626-51. [PMID: 22933563 DOI: 10.1128/mmbr.00010-12] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The mating pheromone a-factor secreted by Saccharomyces cerevisiae is a farnesylated and carboxylmethylated peptide and is unusually hydrophobic compared to other extracellular signaling molecules. Mature a-factor is derived from a precursor with a C-terminal CAAX motif that directs a series of posttranslational reactions, including prenylation, endoproteolysis, and carboxylmethylation. Historically, a-factor has served as a valuable model for the discovery and functional analysis of CAAX-processing enzymes. In this review, we discuss the three modules comprising the a-factor biogenesis pathway: (i) the C-terminal CAAX-processing steps carried out by Ram1/Ram2, Ste24 or Rce1, and Ste14; (ii) two sequential N-terminal cleavage steps, mediated by Ste24 and Axl1; and (iii) export by a nonclassical mechanism, mediated by the ATP binding cassette (ABC) transporter Ste6. The small size and hydrophobicity of a-factor present both challenges and advantages for biochemical analysis, as discussed here. The enzymes involved in a-factor biogenesis are conserved from yeasts to mammals. Notably, studies of the zinc metalloprotease Ste24 in S. cerevisiae led to the discovery of its mammalian homolog ZMPSTE24, which cleaves the prenylated C-terminal tail of the nuclear scaffold protein lamin A. Mutations that alter ZMPSTE24 processing of lamin A in humans cause the premature-aging disease progeria and related progeroid disorders. Intriguingly, recent evidence suggests that the entire a-factor pathway, including all three biogenesis modules, may be used to produce a prenylated, secreted signaling molecule involved in germ cell migration in Drosophila. Thus, additional prenylated signaling molecules resembling a-factor, with as-yet-unknown roles in metazoan biology, may await discovery.
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8
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Turina M, Prodi A, Alfen NKV. Role of the Mf1-1 pheromone precursor gene of the filamentous ascomycete Cryphonectria parasitica. Fungal Genet Biol 2004; 40:242-51. [PMID: 14599892 DOI: 10.1016/s1087-1845(03)00084-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Site-directed recombination was used to obtain a Cryphonectria parasitica strain carrying deletions at the Mf1-1 gene locus. Macroscopic features such as growth rate and conidia production were unaffected by Mf1-1 deletions, but, when a strain containing a complete deletion of Mf1-1 was used as spermatia it was male sterile. The same strain was fully competent as a female parent. Deletion of three of the seven putative pheromone peptide repeats within the gene had no effect on mating. Male fertility of the complete deletion strain was restored when an ectopic copy of the Mf1-1 gene was returned by transformation. Expression of the mating type specific pheromone precursor gene Mf1-1 was stimulated by growth in nutritionally poor liquid media. It was found that age and source of inoculum of liquid cultures influences pheromone precusor gene expression, i.e., conidia did not express Mf1-1 and cultures derived from conidia were significantly delayed in expression of this gene, as were cultures derived from young mycelium. Cultures inoculated with older hyphae, however, expressed Mf1-1 within 1 day after inoculation.
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Affiliation(s)
- Massimo Turina
- Department of Plant Pathology, College of Agricultural and Environmental Sciences, University of California, Davis, 95616-5270, Davis, CA, USA
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9
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Dohlman HG, Thorner JW. Regulation of G protein-initiated signal transduction in yeast: paradigms and principles. Annu Rev Biochem 2002; 70:703-54. [PMID: 11395421 DOI: 10.1146/annurev.biochem.70.1.703] [Citation(s) in RCA: 366] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
All cells have the capacity to evoke appropriate and measured responses to signal molecules (such as peptide hormones), environmental changes, and other external stimuli. Tremendous progress has been made in identifying the proteins that mediate cellular response to such signals and in elucidating how events at the cell surface are linked to subsequent biochemical changes in the cytoplasm and nucleus. An emerging area of investigation concerns how signaling components are assembled and regulated (both spatially and temporally), so as to control properly the specificity and intensity of a given signaling pathway. A related question under intensive study is how the action of an individual signaling pathway is integrated with (or insulated from) other pathways to constitute larger networks that control overall cell behavior appropriately. This review describes the signal transduction pathway used by budding yeast (Saccharomyces cerevisiae) to respond to its peptide mating pheromones. This pathway is comprised by receptors, a heterotrimeric G protein, and a protein kinase cascade all remarkably similar to counterparts in multicellular organisms. The primary focus of this review, however, is recent advances that have been made, using primarily genetic methods, in identifying molecules responsible for regulation of the action of the components of this signaling pathway. Just as many of the constituent proteins of this pathway and their interrelationships were first identified in yeast, the functions of some of these regulators have clearly been conserved in metazoans, and others will likely serve as additional models for molecules that carry out analogous roles in higher organisms.
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Affiliation(s)
- H G Dohlman
- Department of Pharmacology, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut 06536-0812, USA.
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10
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Fowler TJ, DeSimone SM, Mitton MF, Kurjan J, Raper CA. Multiple sex pheromones and receptors of a mushroom-producing fungus elicit mating in yeast. Mol Biol Cell 1999; 10:2559-72. [PMID: 10436012 PMCID: PMC25488 DOI: 10.1091/mbc.10.8.2559] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The mushroom-producing fungus Schizophyllum commune has thousands of mating types defined, in part, by numerous lipopeptide pheromones and their G protein-linked receptors. Compatible combinations of pheromones and receptors encoded by different mating types regulate a pathway of sexual development leading to mushroom formation and meiosis. A complex set of pheromone-receptor interactions maximizes the likelihood of outbreeding; for example, a single pheromone can activate more than one receptor and a single receptor can be activated by more than one pheromone. The current study demonstrates that the sex pheromones and receptors of Schizophyllum, when expressed in Saccharomyces cerevisiae, can substitute for endogenous pheromone and receptor and induce the yeast pheromone response pathway through the yeast G protein. Secretion of active Schizophyllum pheromone requires some, but not all, of the biosynthetic machinery used by the yeast lipopeptide pheromone a-factor. The specificity of interaction among pheromone-receptor pairs in Schizophyllum was reproduced in yeast, thus providing a powerful system for exploring molecular aspects of pheromone-receptor interactions for a class of seven-transmembrane-domain receptors common to a wide range of organisms.
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Affiliation(s)
- T J Fowler
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont 05405, USA
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11
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Abstract
Eukaryotic cells respond to intracellular and extracellular cues to direct asymmetric cell growth and division. The yeast Saccharomyces cerevisiae undergoes polarized growth at several times during budding and mating and is a useful model organism for studying asymmetric growth and division. In recent years, many regulatory and cytoskeletal components important for directing and executing growth have been identified, and molecular mechanisms have been elucidated in yeast. Key signaling pathways that regulate polarization during the cell cycle and mating response have been described. Since many of the components important for polarized cell growth are conserved in other organisms, the basic mechanisms mediating polarized cell growth are likely to be universal among eukaryotes.
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Affiliation(s)
- K Madden
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520-8103, USA
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12
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Abstract
Both agonistic and sexual animal displays often involve more than one performance of some specific display action. Since repetition is energetically costly there must be good reasons why a signaller should carry out such repetitive actions, rather than simply displaying once. We briefly review three different 'reasons' which arise from three different receiver assessment rules: when assessment is based on the average magnitude of all display actions so far, the reason for the repetition is to improve the accuracy of the estimate (model A); when the assessment is based solely on the action of greatest magnitude so far, the repetition is to replace the signal with one of greater magnitude (model B); when the assessment is based on the cumulative sum of all display actions so far, the repetition is to augment that sum (model C). We discuss how to characterize each case from an understanding of its expected optimal behaviour as predicted by formal models. For model A the mean magnitude of display actions should stay constant and the contest duration should depend on relative qualities. In models B and C the encounter duration depends only on the weaker participant. In model B each display action is greater than the previous, but only a small number of steps are expected. In model C the magnitude of display actions can either escalate, stay constant, or even decrease. The displays of cichlid fish, the roaring contests of red deer, Cervus elaphusthe calling of Blanchard's cricket frogs, Acris crepitans blanchardiand the pheromonal exchanges of yeast gametes are used as illustrative examples.
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Affiliation(s)
- RJH Payne
- BBSRC/NERC Ecology and Behaviour Group, Department of Zoology, University of Oxford
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13
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Analysis of the structural genes encoding M-factor in the fission yeast Schizosaccharomyces pombe: identification of a third gene, mfm3. Mol Cell Biol 1994. [PMID: 8196631 DOI: 10.1128/mcb.14.6.3895] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We previously identified two genes, mfm1 and mfm2, with the potential to encode the M-factor mating pheromone of the fission yeast Schizosaccharomyces pombe (J. Davey, EMBO J. 11:951-960, 1992), but further analysis revealed that a mutant strain lacking both genes still produced active M-factor. Here we describe the isolation and characterization of a third M-factor gene, mfm3. A mutant lacking all three genes fails to produce M-factor, indicating that all functional M-factor genes now have been identified. The triple mutant exhibits an absolute mating defect in M cells, a defect that is not rescued by addition of exogenous M-factor. A mutational analysis reveals that all three mfm genes contribute to the production of M-factor. Their transcription is limited to M cells and requires the mat1-Mc and ste11 gene products. Each gene is induced when the cells are starved of nitrogen and further induced by a pheromone signal. Additionally, the signal transduction machinery associated with the pheromone response is required for transcription of the mfm genes in both stimulated and unstimulated cells.
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14
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Banuett F, Herskowitz I. Identification of fuz7, a Ustilago maydis MEK/MAPKK homolog required for a-locus-dependent and -independent steps in the fungal life cycle. Genes Dev 1994; 8:1367-78. [PMID: 7926737 DOI: 10.1101/gad.8.12.1367] [Citation(s) in RCA: 154] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Ustilago maydis is a plant pathogenic Basidiomycete fungus that exhibits dimorphism--it has a haploid, yeast-like phase and a dikaryotic, filamentous phase that is pathogenic. Establishment and maintenance of these two forms are controlled by two mating type loci, a and b. The a locus is thought to govern fusion of haploid cells to form a dikaryon and is also required for filamentous growth of the dikaryon. It encodes two components of a pheromone response pathway: pheromones and receptors. We report the identification of the U. maydis fuz7 gene, which codes for a putative dual specificity serine/threonine tyrosine kinase of the MAP kinase kinase (MAPKK/MEK) family, by homology with other members of the family. Analysis of mutants deleted for fuz7 shows that it participates in different facets of the life cycle: It is necessary for a-locus-dependent processes, such as conjugation tube formation, filament formation, and maintenance of filamentous growth, and for a-locus-independent processes, such as tumor induction and teliospore germination. fuz7 is the first U. maydis gene distinct from the b locus required for fungal pathogenicity. We propose that fuz7 is involved in at least two pathways, one of which responds to the pheromones coded by the a locus and the other to putative signals from the plant.
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Affiliation(s)
- F Banuett
- Department of Biochemistry and Biophysics, School of Medicine, University of California San Francisco 94143-0448
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15
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Kjaerulff S, Davey J, Nielsen O. Analysis of the structural genes encoding M-factor in the fission yeast Schizosaccharomyces pombe: identification of a third gene, mfm3. Mol Cell Biol 1994; 14:3895-905. [PMID: 8196631 PMCID: PMC358756 DOI: 10.1128/mcb.14.6.3895-3905.1994] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We previously identified two genes, mfm1 and mfm2, with the potential to encode the M-factor mating pheromone of the fission yeast Schizosaccharomyces pombe (J. Davey, EMBO J. 11:951-960, 1992), but further analysis revealed that a mutant strain lacking both genes still produced active M-factor. Here we describe the isolation and characterization of a third M-factor gene, mfm3. A mutant lacking all three genes fails to produce M-factor, indicating that all functional M-factor genes now have been identified. The triple mutant exhibits an absolute mating defect in M cells, a defect that is not rescued by addition of exogenous M-factor. A mutational analysis reveals that all three mfm genes contribute to the production of M-factor. Their transcription is limited to M cells and requires the mat1-Mc and ste11 gene products. Each gene is induced when the cells are starved of nitrogen and further induced by a pheromone signal. Additionally, the signal transduction machinery associated with the pheromone response is required for transcription of the mfm genes in both stimulated and unstimulated cells.
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Affiliation(s)
- S Kjaerulff
- Department of Genetics, University of Copenhagen, Denmark
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16
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Abstract
The gametes of many lower eukaryotic organisms emit pheromones that attract gametes of the opposite mating type or sex. Gametes move or grow in the direction of the highest pheromone concentration, suggesting that the strength of the pheromonal signal is used to infer proximity, or that the strongest signal is most likely to be notice. Here I offer a new explanation of pheromonal signalling and chemotaxis in gametes. I show that pheromonal signals can be interpreted as sexually selected traits that honestly advertise variation in quality among gametes, given that signals are costly to produce and that gametes compete; by 'quality' I refer to some aspect of a gamete's fitness. A gamete's preference for a mating partner, then, is predicted to vary with the quality of a prospective partner as inferred from the strength of its signal. This view can explain characteristics of the signalling and mate selection behaviours of gametes that are not predicted by models of mate choice based on proximity or 'passive attraction' to the strongest signal. These include repeated partner exchanges, escalated exchanges of mating pheromones, and rejection of gametes that signal at low levels.
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Affiliation(s)
- M Pagel
- School of Mathematical Sciences, Queen Mary and Westfield College, University of London, UK
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17
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Affiliation(s)
- G W Gooday
- Department of Molecular and Cell Biology, University of Aberdeen, UK
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18
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Madden K, Snyder M. Specification of sites for polarized growth in Saccharomyces cerevisiae and the influence of external factors on site selection. Mol Biol Cell 1992; 3:1025-35. [PMID: 1421575 PMCID: PMC275663 DOI: 10.1091/mbc.3.9.1025] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Many eucaryotic cell types exhibit polarized cell growth and polarized cell division at nonrandom sites. The sites of polarized growth were investigated in G1 arrested haploid Saccharomyces cerevisiae cells. When yeast cells are arrested during G1 either by treatment with alpha-factor or by shifting temperature-sensitive cdc28-1 cells to the restrictive temperature, the cells form a projection. Staining with Calcofluor reveals that in both cases the projection usually forms at axial sites (i.e., next to the previous bud scar); these are the same sites where bud formation is expected to occur. These results indicate that sites of polarized growth are specified before the end of G1. Sites of polarized growth can be influenced by external conditions. Cells grown to stationary phase and diluted into fresh medium preferentially select sites for polarized growth opposite the previous bud scar (i.e., distal sites). Incubation of cells in a mating mixture results in projection formation at nonaxial sites: presumably cells form projections toward their mating partner. These observations have important implications in understanding three aspects of cell polarity in yeast: 1) how yeast cell shape is influenced by growth conditions 2) how sites of polarized growth are chosen, and 3) the pathway by which polarity is affected and redirected during the mating process.
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Affiliation(s)
- K Madden
- Department of Biology, Yale University, New Haven, Connecticut 06511
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19
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Hwang-Shum JJ, Hagen DC, Jarvis EE, Westby CA, Sprague GF. Relative contributions of MCM1 and STE12 to transcriptional activation of a- and alpha-specific genes from Saccharomyces cerevisiae. MOLECULAR & GENERAL GENETICS : MGG 1991; 227:197-204. [PMID: 1905781 DOI: 10.1007/bf00259671] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have examined the relative contributions of MCM1 and STE12 to the transcription of the a-specific STE2 gene by using a 367 bp fragment from the STE2 5'-noncoding region to drive expression of a reporter lacZ gene. Mutation of the MCM1 binding site destroyed MCM1.alpha 2-mediated repression in alpha cells and dramatically reduced expression in a cells. The residual expression was highly stimulated by exposure of cells to pheromone. Likewise, the loss of STE12 function reduced lacZ expression driven by the wild-type STE2 fragment. In the absence of both MCM1 and STE12 functions, no residual expression was observed. Thus, the STE2 fragment appears to contain two distinct upstream activation sequences (UASs), one that is responsible for the majority of expression in cells not stimulated by pheromone, and one that is responsible for increased expression upon pheromone stimulation. In further support of this idea, a chemically synthesized version of the STE2 MCM1 binding site had UAS activity, but the activity was neither stimulated by pheromone nor reduced in ste12 mutants. Although transcription of alpha-specific genes also requires both MCM1 and STE12, these genes differ from a-specific genes in that they have a single, MCM1-dependent UAS system. The activity of the minimal 26 bp UAS from the alpha-specific STE3 gene was both stimulated by pheromone and reduced in ste12 mutants. These data suggest that at alpha-specific genes STE12 and MCM1 exert their effects through a single UAS.
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Affiliation(s)
- J J Hwang-Shum
- Institute of Molecular Biology, University of Oregon, Eugene 97403
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20
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Jackson CL, Hartwell LH. Courtship in S. cerevisiae: both cell types choose mating partners by responding to the strongest pheromone signal. Cell 1990; 63:1039-51. [PMID: 2257622 DOI: 10.1016/0092-8674(90)90507-b] [Citation(s) in RCA: 171] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We demonstrate that during the courtship stage of conjugation, S. cerevisiae a cells choose the alpha cell producing the highest level of pheromone from among potential mating partners. From this result and that for alpha cells we conclude that both a and alpha cells act as signaling cells during courtship, that both cell types respond by discriminating different levels of signal, and that the signals are the mating pheromones. Responding cells that are supersensitive to signal fail to discriminate pheromone-producing from nonproducing cells to an extent that depends on their degree of supersensitivity. We propose that partner selection in S. cerevisiae results from polarized morphogenesis of a responding cell in the direction of highest pheromone concentration and that cells defective in discriminating this gradient execute a default pathway in which an adjacent cell is selected at random.
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Affiliation(s)
- C L Jackson
- Department of Genetics, University of Washington, Seattle 98195
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21
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Proteau G, Gelaznikas R, Merante F. The isolation of biologically active mating pheromone, a-factor, from the yeast, Saccharomyces cerevisiae. Biochem Biophys Res Commun 1990; 170:182-6. [PMID: 2164801 DOI: 10.1016/0006-291x(90)91257-s] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Haploid cell-types of baker's yeast, Saccharomyces cerevisiae, secrete pheromones which are essential for conjugation. Recently a putative structure for the elusive a-factor pheromone has been reported. In this report we present a procedure to obtain a-factor from batch cultures of cells using hydrophobic Amberlite XAD-2 resin in the growth medium with subsequent differential washings of the resin with organic solvents. We have determined the biological activity of the a-factor preparation by verifying that there is an increase in transcription of the a-factor receptor gene, STE3, by Northern analysis of STE3 mRNA before and after exposure of the appropriate cell type to a-factor. Furthermore, a beta-galactosidase assay of the putative receptor gene fused to the lacZ gene, coding for beta-galactosidase (STE3-lacZ), was done to quantify the biological activity of the a-factor.
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Affiliation(s)
- G Proteau
- Department of Zoology, Erindale College, University of Toronto, Mississauga, Ontario, Canada
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22
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Abstract
During conjugation in Saccharomyces cerevisiae, two cells of opposite mating type (MATa and MAT alpha) fuse to form a diploid zygote. Conjugation requires that each cell locate an appropriate mating partner. To investigate how yeast cells select a mating partner, we developed a competition mating assay in which wild-type MAT alpha cells have a choice of two MATa cell mating partners. We first demonstrated that sterile MAT alpha 1 cells (expressing no a- or alpha-specific gene products) do not compete with fertile MATa cells in the assay; hence, wild-type MATa and MAT alpha cells can efficiently locate an appropriate mating partner. Second, we showed that a MATa strain need not be fertile to compete with a fertile MATa strain in the assay. This result defines an early step in conjugation, which we term courtship. We showed that the ability to agglutinate is not necessary in MATa cells for courtship but that production of a-pheromone and response to alpha-pheromone are necessary. Thus, MATa cells must not only transmit but must also receive and then respond to information for effective courtship; hence, there is a "conversation" between the courting cells. We showed that the only alpha-pheromone-induced response necessary in MATa cells for courtship is production of a-pheromone. In all cases tested, a strain producing a higher level of a-pheromone was more proficient in courtship than one producing a lower level. We propose that during courtship, a MAT alpha cell selects the adjacent MATa cell producing the highest level of a-pheromone.
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23
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Jackson CL, Hartwell LH. Courtship in Saccharomyces cerevisiae: an early cell-cell interaction during mating. Mol Cell Biol 1990; 10:2202-13. [PMID: 2183023 PMCID: PMC360568 DOI: 10.1128/mcb.10.5.2202-2213.1990] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
During conjugation in Saccharomyces cerevisiae, two cells of opposite mating type (MATa and MAT alpha) fuse to form a diploid zygote. Conjugation requires that each cell locate an appropriate mating partner. To investigate how yeast cells select a mating partner, we developed a competition mating assay in which wild-type MAT alpha cells have a choice of two MATa cell mating partners. We first demonstrated that sterile MAT alpha 1 cells (expressing no a- or alpha-specific gene products) do not compete with fertile MATa cells in the assay; hence, wild-type MATa and MAT alpha cells can efficiently locate an appropriate mating partner. Second, we showed that a MATa strain need not be fertile to compete with a fertile MATa strain in the assay. This result defines an early step in conjugation, which we term courtship. We showed that the ability to agglutinate is not necessary in MATa cells for courtship but that production of a-pheromone and response to alpha-pheromone are necessary. Thus, MATa cells must not only transmit but must also receive and then respond to information for effective courtship; hence, there is a "conversation" between the courting cells. We showed that the only alpha-pheromone-induced response necessary in MATa cells for courtship is production of a-pheromone. In all cases tested, a strain producing a higher level of a-pheromone was more proficient in courtship than one producing a lower level. We propose that during courtship, a MAT alpha cell selects the adjacent MATa cell producing the highest level of a-pheromone.
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Affiliation(s)
- C L Jackson
- Department of Genetics, University of Washington, Seattle 98195
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24
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Regulation of alpha-factor production in Saccharomyces cerevisiae: a-factor pheromone-induced expression of the MF alpha 1 and STE13 genes. Mol Cell Biol 1989. [PMID: 2685554 DOI: 10.1128/mcb.9.10.4507] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Production of the mating pheromone alpha-factor was examined in Saccharomyces cerevisiae MAT alpha cells that had been exposed to the mating pheromone a-factor. A 2-h treatment with a-factor caused a significant increase in alpha-factor concentration in the medium as demonstrated by a halo assay. MF alpha 1 is one of the two genes coding for a precursor of alpha-factor. A Northern (RNA) analysis of total RNA from a-factor-treated MAT alpha cells revealed a rapid two- to threefold increase in MF alpha 1 transcript levels, reaching maximum within 60 min of exposure to the pheromone. Pheromone induction did not require ongoing protein synthesis. a-Factor-induced MF alpha 1 expression was quantitated by analysis of an MF alpha 1::SUC2 fusion gene whose product was assayed for invertase activity. Expression of the MF alpha 1::SUC2 gene in MAT alpha cells responded to the a-factor signal like the chromosomal version of MF alpha 1. Maturation of the alpha-factor precursor involves three proteolytic activities which are encoded by the KEX1, KEX2, and STE13 genes, respectively. Two of these genes, namely, KEX2 and STE13, were examined for pheromone-induced expression. Only the STE13 gene exhibited pheromone induction at the transcriptional level.
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25
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Abstract
The specialized sets of genes that determine different cell types in yeast are controlled by combinations of DNA-binding proteins some of which are present only in certain cell types whereas others are present in all cell types. Final differentiation requires an inductive signal that triggers both gene transcription and cell-cycle arrest. Synthesis of the proteins coded by the 'master regulatory' mating-type locus is regulated so as to generate a heterogeneous mitotic cell population containing a stem-cell lineage.
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Affiliation(s)
- I Herskowitz
- Department of Biochemistry and Biophysics, University of California, San Francisco 94143
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26
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Achstetter T. Regulation of alpha-factor production in Saccharomyces cerevisiae: a-factor pheromone-induced expression of the MF alpha 1 and STE13 genes. Mol Cell Biol 1989; 9:4507-14. [PMID: 2685554 PMCID: PMC362535 DOI: 10.1128/mcb.9.10.4507-4514.1989] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Production of the mating pheromone alpha-factor was examined in Saccharomyces cerevisiae MAT alpha cells that had been exposed to the mating pheromone a-factor. A 2-h treatment with a-factor caused a significant increase in alpha-factor concentration in the medium as demonstrated by a halo assay. MF alpha 1 is one of the two genes coding for a precursor of alpha-factor. A Northern (RNA) analysis of total RNA from a-factor-treated MAT alpha cells revealed a rapid two- to threefold increase in MF alpha 1 transcript levels, reaching maximum within 60 min of exposure to the pheromone. Pheromone induction did not require ongoing protein synthesis. a-Factor-induced MF alpha 1 expression was quantitated by analysis of an MF alpha 1::SUC2 fusion gene whose product was assayed for invertase activity. Expression of the MF alpha 1::SUC2 gene in MAT alpha cells responded to the a-factor signal like the chromosomal version of MF alpha 1. Maturation of the alpha-factor precursor involves three proteolytic activities which are encoded by the KEX1, KEX2, and STE13 genes, respectively. Two of these genes, namely, KEX2 and STE13, were examined for pheromone-induced expression. Only the STE13 gene exhibited pheromone induction at the transcriptional level.
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Affiliation(s)
- T Achstetter
- Institut für Botanik, Universität Regensburg, Federal Republic of Germany
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27
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Errede B, Ammerer G. STE12, a protein involved in cell-type-specific transcription and signal transduction in yeast, is part of protein-DNA complexes. Genes Dev 1989; 3:1349-61. [PMID: 2558054 DOI: 10.1101/gad.3.9.1349] [Citation(s) in RCA: 233] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The STE12 gene of Saccharomyces cerevisiae is essential for the expression of genes required for mating, such as those involved in pheromone response, and for genes unrelated to mating but regulated by the presence of an adjacent copy of the transposable element Ty1. We show that the STE12 protein is a component of specific DNA-protein complexes that form with transcriptional control elements from Ty1 and the alpha-pheromone receptor gene STE2. Although a sequence involved in pheromone-dependent transcriptional activation is protected in both complexes, competition experiments indicate that the complexes are intrinsically different from each other. We show that another factor involved in cell-type-specific transcription, PRTF/GRM, is a component of the complex with the STE2 fragment but not the Ty1 fragment. We propose that the STE12 product interacts with different transcription factors in different sequence contexts and that PRTF/GRM is one of these factors.
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Affiliation(s)
- B Errede
- Department of Chemistry, University of North Carolina, Chapel Hill 27599
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28
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Appeltauer U, Achstetter T. Hormone-induced expression of the CHS1 gene from Saccharomyces cerevisiae. EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 181:243-7. [PMID: 2523800 DOI: 10.1111/j.1432-1033.1989.tb14718.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
When MATa cells of Saccharomyces cerevisiae have been treated with the mating hormone alpha-factor an increase in chitin synthase zymogen, as well as chitin content in the cell-wall fraction, have been reported. With a DNA probe derived from the cloned CHS1 gene that codes for chitin synthase I [Bulawa, C. E., Slater, M., Cabib, E., Au-Young, J., Sburlati, A., Adair, W. L. and Robbins, P. (1986) Cell 46, 213-225] a Northern analysis was conducted of CHS1-specific transcripts. alpha-Factor-treated MATa cells revealed more than sixfold elevated steady-state levels of CHS1 mRNA as compared to control cells. MAT alpha cells responded the same way when treated with a-factor although induction rate was somewhat smaller. After hormone application a rapid increase in CHS1 mRNA levels could be observed that occurred also in the absence of ongoing protein synthesis. In order to minimize possible side effects of CHS1-coding sequences on expression and mRNA stability a CHS1::SUC2 chimaeric gene was constructed where 730 bp of the CHS1 promoter region (+20 bp of the coding region) were fused in frame to a fragment of the SUC2 coding region. The fusion protein exhibits invertase activity that has been used to monitor CHS1 promoter activity. By analysis of shortened versions of the CHS1 promoter a 94-bp DNA fragment has been identified that confers hormone inducibility to the CHS1 promoter. 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]. This heptamer may represent the cis-acting element involved in mating-hormone-mediated gene expression in yeast.
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Affiliation(s)
- U Appeltauer
- Lehrstuhl für Pflanzenphysiologie und Zellbiologie, Universität Regensburg, France
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29
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DAF1, a mutant gene affecting size control, pheromone arrest, and cell cycle kinetics of Saccharomyces cerevisiae. Mol Cell Biol 1989. [PMID: 3062366 DOI: 10.1128/mcb.8.11.4675] [Citation(s) in RCA: 239] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The mating pheromone alpha-factor arrests Saccharomyces cerevisiae MATa cells in the G1 phase of the cell cycle. Size control is also exerted in G1, since cells do not exit G1 until they have attained a critical size. A dominant mutation (DAF1-1) which causes both alpha-factor resistance and small cell size (volume about 0.6-fold that of the wild type) has been isolated and characterized genetically and by molecular cloning. Several alpha-factor-induced mRNAs were induced equivalently in daf1+ and DAF1-1 cells. The DAF1-1 mutation consisted of a termination codon two-thirds of the way through the daf1+ coding sequence. A chromosomal deletion of DAF1 produced by gene transplacement increased cell volume about 1.5-fold; thus, DAF1-1 may be a hyperactive or deregulated allele of a nonessential gene involved in G1 size control. Multiple copies of DAF1-1 also greatly reduced the duration of the G1 phase of the cell cycle.
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30
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31
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Cross FR. DAF1, a mutant gene affecting size control, pheromone arrest, and cell cycle kinetics of Saccharomyces cerevisiae. Mol Cell Biol 1988; 8:4675-84. [PMID: 3062366 PMCID: PMC365557 DOI: 10.1128/mcb.8.11.4675-4684.1988] [Citation(s) in RCA: 173] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The mating pheromone alpha-factor arrests Saccharomyces cerevisiae MATa cells in the G1 phase of the cell cycle. Size control is also exerted in G1, since cells do not exit G1 until they have attained a critical size. A dominant mutation (DAF1-1) which causes both alpha-factor resistance and small cell size (volume about 0.6-fold that of the wild type) has been isolated and characterized genetically and by molecular cloning. Several alpha-factor-induced mRNAs were induced equivalently in daf1+ and DAF1-1 cells. The DAF1-1 mutation consisted of a termination codon two-thirds of the way through the daf1+ coding sequence. A chromosomal deletion of DAF1 produced by gene transplacement increased cell volume about 1.5-fold; thus, DAF1-1 may be a hyperactive or deregulated allele of a nonessential gene involved in G1 size control. Multiple copies of DAF1-1 also greatly reduced the duration of the G1 phase of the cell cycle.
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Affiliation(s)
- F R Cross
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98104
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32
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Pheromonal regulation and sequence of the Saccharomyces cerevisiae SST2 gene: a model for desensitization to pheromone. Mol Cell Biol 1988. [PMID: 2830483 DOI: 10.1128/mcb.7.12.4169] [Citation(s) in RCA: 114] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Strains of both haploid mating types containing sst2 mutations are altered in response to pheromone; MATa sst2 cells are supersensitive to alpha-factor, and MAT alpha sst2 cells are supersensitive to a-factor. This phenotype suggests that SST2 encodes a component of the pheromone response pathway that is common to both mating types. We have cloned the SST2 gene by isolation of multicopy plasmids that complement the sst2-1 mutation. One such plasmid contained a 4.5-kilobase HindIII fragment that was able to complement the sst2-1 mutation in high or low copy number, integrated at the SST2 locus, and resulted in an sst2 phenotype when disrupted, indicating that this fragment contained the SST2 gene. We identified the functional region of the complementing DNA fragment by transposon mutagenesis. Sequencing of this fragment identified an open reading frame encoding 698 amino acids at a position that correlated well with the functional region. Expression of an Sst2-beta-galactosidase fusion was haploid specific and induced by exposure to pheromone. We discuss a model in which induction of the SST2 product results in inhibition of a component of the pheromone response pathway, resulting in desensitization to pheromone.
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33
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Dietzel C, Kurjan J. Pheromonal regulation and sequence of the Saccharomyces cerevisiae SST2 gene: a model for desensitization to pheromone. Mol Cell Biol 1987; 7:4169-77. [PMID: 2830483 PMCID: PMC368097 DOI: 10.1128/mcb.7.12.4169-4177.1987] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Strains of both haploid mating types containing sst2 mutations are altered in response to pheromone; MATa sst2 cells are supersensitive to alpha-factor, and MAT alpha sst2 cells are supersensitive to a-factor. This phenotype suggests that SST2 encodes a component of the pheromone response pathway that is common to both mating types. We have cloned the SST2 gene by isolation of multicopy plasmids that complement the sst2-1 mutation. One such plasmid contained a 4.5-kilobase HindIII fragment that was able to complement the sst2-1 mutation in high or low copy number, integrated at the SST2 locus, and resulted in an sst2 phenotype when disrupted, indicating that this fragment contained the SST2 gene. We identified the functional region of the complementing DNA fragment by transposon mutagenesis. Sequencing of this fragment identified an open reading frame encoding 698 amino acids at a position that correlated well with the functional region. Expression of an Sst2-beta-galactosidase fusion was haploid specific and induced by exposure to pheromone. We discuss a model in which induction of the SST2 product results in inhibition of a component of the pheromone response pathway, resulting in desensitization to pheromone.
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Affiliation(s)
- C Dietzel
- Department of Biological Sciences, Columbia University, New York, New York 10027
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34
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Abstract
The Saccharomyces cerevisiae STE2 gene, which is required for pheromone response and conjugation specifically in mating-type a cells, was cloned by complementation of the ste2 mutation. Transcription of STE2 is repressed by the MAT alpha 2 gene product, so that the 1.4-kilobase STE2 RNA is detected only in a or mat alpha 2 strains, not in alpha or a/alpha cells. However, STE2 RNA levels are also increased by the mating pheromone alpha-factor and decreased in strains bearing mutations in the nonspecific STE4 gene. Regulation of STE2 expression in a cells is therefore achieved by several mechanisms.
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35
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Grossman A, Klein H, Becker JM, Naider F. Yeast alpha-factor and somatostatin enhance binding of [3H]estradiol to proteins in rat pancreas and Saccharomyces cerevisiae. JOURNAL OF STEROID BIOCHEMISTRY 1986; 25:299-304. [PMID: 2877118 DOI: 10.1016/0022-4731(86)90239-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Pancreatic tissue contains an [3H]estradiol-binding protein that requires a coligand in the steroid-binding reaction. The endogenous coligand appears to be the tetradecapeptide somatostatin. Yeast alpha-factor, a tridecapeptide pheromone that induces conjugation between haploid cells of opposite mating type, was found to be as effective as somatostatin in enhancing specific binding of [3H]estradiol to partially purified pancreatic protein. Supernatant fractions from yeast cells also contain an [3H]estradiol-binding protein. alpha-Factor can enhance specific binding of [3H]estradiol to such yeast fractions. Somatostatin, somatostatin analogues, and an analogue of alpha-factor enhanced binding of [3H]estradiol but did not inhibit cell growth or induce morphological changes in S. cerevisiae. Thus, it appears that coligand-requiring [3H]estradiol-binding activity and mating in yeast are not directly related.
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36
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Hartig A, Holly J, Saari G, MacKay VL. Multiple regulation of STE2, a mating-type-specific gene of Saccharomyces cerevisiae. Mol Cell Biol 1986; 6:2106-14. [PMID: 3023919 PMCID: PMC367751 DOI: 10.1128/mcb.6.6.2106-2114.1986] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The Saccharomyces cerevisiae STE2 gene, which is required for pheromone response and conjugation specifically in mating-type a cells, was cloned by complementation of the ste2 mutation. Transcription of STE2 is repressed by the MAT alpha 2 gene product, so that the 1.4-kilobase STE2 RNA is detected only in a or mat alpha 2 strains, not in alpha or a/alpha cells. However, STE2 RNA levels are also increased by the mating pheromone alpha-factor and decreased in strains bearing mutations in the nonspecific STE4 gene. Regulation of STE2 expression in a cells is therefore achieved by several mechanisms.
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37
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Hagen DC, McCaffrey G, Sprague GF. Evidence the yeast STE3 gene encodes a receptor for the peptide pheromone a factor: gene sequence and implications for the structure of the presumed receptor. Proc Natl Acad Sci U S A 1986; 83:1418-22. [PMID: 3006051 PMCID: PMC323087 DOI: 10.1073/pnas.83.5.1418] [Citation(s) in RCA: 216] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Haploid yeast cells of the a mating type secrete a peptide pheromone, a factor, which acts on cells of the alpha mating type to prepare them for conjugation. We show that the STE3 gene, which is required for mating only by alpha cells and is transcribed only in alpha cells, likely encodes a cell-surface receptor for a factor. This view is based on three findings. First, wild-type Ste3 product is required for response to the pheromone: mutants with any one of five different ste3 mutations are unresponsive to a factor. Second, a hybrid Ste3-beta-galactosidase protein encoded by a STE3-lacZ gene fusion fractionates to the particulate fraction of yeast cell extracts, suggesting that Ste3 is a membrane protein. Finally, the DNA sequence of STE3, which we report here, encodes a protein of 470 amino acid residues that contains seven distinct hydrophobic segments of sufficient length to span a lipid bilayer.
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38
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Nakayama N, Miyajima A, Arai K. Nucleotide sequences of STE2 and STE3, cell type-specific sterile genes from Saccharomyces cerevisiae. EMBO J 1985; 4:2643-8. [PMID: 16453635 PMCID: PMC554555 DOI: 10.1002/j.1460-2075.1985.tb03982.x] [Citation(s) in RCA: 194] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The nucleotide sequences of STE2 and STE3, cell type-specific sterile genes of Saccharomyces cerevisiae, were determined; major open reading frames encode 431 and 470 amino acids, respectively. STE2 and STE3 proteins seem to be folded in a similar fashion and are likely to be membrane-bound. Both consist of seven hydrophobic segments in each NH(2)-terminal region with a long hydrophilic domain in each COOH-terminal region. However, the two putative gene products do not exhibit extensive sequence homology. The STE2 protein has no obvious hydrophobic signal peptide; the NH(2) terminus of the STE3 protein might serve as a signal peptide. The STE2 transcript, 1.7 kb, was detected in MATa strains but not in MATalpha strains, while the STE3 transcript, also 1.7 kb, was detected only in MATalpha cells. In STE2, two canonical TATA sequences are located 18 and 27 bp upstream of the mRNA start site, which has been mapped 32 bp before the initiator ATG codon, while STE3 contains a similar sequence (TATAGA), which is preceded by a long AT sequence, 140 bp upstream of the initiator ATG codon. Transcription of STE2 in a cells seems to be enhanced by exogenous alpha-factor.
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Affiliation(s)
- N Nakayama
- DNAX Research Institute of Molecular and Cellular Biology, 901 California Avenue, Palo Alto, CA 94304, USA
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Hagen DC, Sprague GF. Induction of the yeast alpha-specific STE3 gene by the peptide pheromone a-factor. J Mol Biol 1984; 178:835-52. [PMID: 6436496 DOI: 10.1016/0022-2836(84)90314-0] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The yeast Saccharomyces cerevisiae exhibits two mating types, a and alpha. Efficient mating of a and alpha cells requires the action of peptide pheromones secreted by each cell type. For example, a cells secrete a-factor, which alters the physiology of alpha cells, thereby preparing those cells for mating. To investigate the mechanism by which the pheromones act on the target cells, we have examined the effect of a-factor on expression of the STE3 gene, a gene which is required for mating by alpha cells and which is expressed only in alpha cells. We have monitored STE3 expression by two assays: RNA production from the chromosomal STE3 locus and beta-galactosidase activity produced from a plasmid-borne STE3-lacZ gene fusion. By both assays we show that a-factor induces a rapid increase in STE3 expression. Induction of STE3 RNA occurs even if protein synthesis is blocked by cycloheximide. Using temperature-sensitive cell division cycle mutants, we have also shown that induction occurs in cells arrested at several discrete positions in the cell cycle. These results demonstrate (1) that induction of STE3 expression by a-factor is a primary response to the pheromone, and (2) that alpha cells are capable of responding to a-factor regardless of their position in the cell cycle.
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