scholarly journals MOD-D, a Gα Subunit of the Fungus Podospora anserina, Is Involved in Both Regulation of Development and Vegetative Incompatibility

Genetics ◽  
1999 ◽  
Vol 152 (2) ◽  
pp. 519-528 ◽  
Author(s):  
Gabriel Loubradou ◽  
Joël Bégueret ◽  
Béatrice Turcq
Keyword(s):  
Molecular Mechanisms ◽  
Biological Function ◽  
Podospora Anserina ◽  
Developmental Pathways ◽  
Vegetative Incompatibility ◽  
Developmental Defects ◽  
Camp Pathway ◽  
Suppressor Effect ◽  
Mutant Strains ◽  
Incompatibility Reaction

Abstract Cell death via vegetative incompatibility is widespread in fungi but molecular mechanism and biological function of the process are poorly understood. One way to investigate this phenomenon was to study genes named mod that modified incompatibility reaction. In this study, we cloned the mod-D gene that encodes a Gα protein. The mod-D mutant strains present developmental defects. Previously, we showed that the mod-E gene encodes an HSP90. The mod-E1 mutation suppresses both vegetative incompatibility and developmental defects due to the mod-D mutation. Moreover, we isolated the PaAC gene, which encodes an adenylate cyclase, as a partial suppressor of the mod-D1 mutation. Our previous results showed that the molecular mechanisms involved in vegetative incompatibility and developmental pathways are connected, suggesting that vegetative incompatibility may result from disorders in some developmental steps. Our new result corroborates the involvement of mod genes in signal transduction pathways. As expected, we showed that an increase in the cAMP level is able to suppress the defects in vegetative growth due to the mod-D1 mutation. However, cAMP increase has no influence on the suppressor effect of the mod-D1 mutation on vegetative incompatibility, suggesting that this suppressor effect is independent of the cAMP pathway.

A Mutation in an HSP90 Gene Affects the Sexual Cycle and Suppresses Vegetative Incompatibility in the Fungus Podospora anserina

Genetics ◽  
1997 ◽  
Vol 147 (2) ◽  
pp. 581-588
Author(s):  
Gabriel Loubradou ◽  
Joel Bégueret ◽  
Béatrice Turcq
Keyword(s):  
Signal Transduction ◽  
Molecular Mechanisms ◽  
Biological Function ◽  
Molecular Level ◽  
Signal Transduction Pathway ◽  
Podospora Anserina ◽  
Sexual Cycle ◽  
Transduction Pathway ◽  
Vegetative Incompatibility ◽  
Developmental Defects

Vegetative incompatibility is widespread in fungi but its molecular mechanism and biological function are still poorly understood. A way to study vegetative incompatibility is to investigate the function of genes whose mutations suppress this phenomenon. In Podospora anserina, these genes are known as mod genes. In addition to suppressing vegetative incompatibility, mod mutations cause some developmental defects. This suggests that the molecular mechanisms of vegetative incompatibility and development pathways are interconnected. The mod-E1 mutation was isolated as a suppressor of the developmental defects of the mod-D2 strain. We show here that mod-E1 also partially suppresses vegetative incompatibility, strengthening the link between development and vegetative incompatibility. mod-E1 is the first suppressor of vegetative incompatibility characterized at the molecular level. It encodes a member of the Hsp90 family, suggesting that development and vegetative incompatibility use common steps of a signal transduction pathway. The involvement of mod-E in the sexual cycle has also been further investigated.

scholarly journals Regulation of Gene Expression During the Vegetative Incompatibility Reaction in Podospora anserina: Characterization of Three Induced Genes

Genetics ◽  
1998 ◽  
Vol 150 (2) ◽  
pp. 633-641
Author(s):  
Nathalie Bourges ◽  
Alexis Groppi ◽  
Christian Barreau ◽  
Corinne Clavé ◽  
Joël Bégueret
Keyword(s):  
Gene Expression ◽  
Expression Profiles ◽  
Regulation Of Gene Expression ◽  
Podospora Anserina ◽  
In Vitro Translation ◽  
Vegetative Incompatibility ◽  
Two Dimensional Gel Electrophoresis ◽  
Small Proteins ◽  
Mrna Content ◽  
Incompatibility Reaction

Abstract Vegetative incompatibility in fungi limits the formation of viable heterokaryons. It results from the coexpression of incompatible genes in the heterokaryotic cells and leads to a cell death reaction. In Podospora anserina, a modification of gene expression takes place during this reaction, including a strong decrease of total RNA synthesis and the appearance of a new set of proteins. Using in vitro translation of mRNA and separation of protein products by two-dimensional gel electrophoresis, we have shown that the mRNA content of cells is qualitatively modified during the progress of the incompatibility reaction. Thus, gene expression during vegetative incompatibility is regulated, at least in part, by variation of the mRNA content of specific genes. A subtractive cDNA library enriched in sequences preferentially expressed during incompatibility was constructed. This library was used to identify genomic loci corresponding to genes whose mRNA is induced during incompatibility. Three such genes were characterized and named idi genes for genes induced during incompatibility. Their expression profiles suggest that they may be involved in different steps of the incompatibility reaction. The putative IDI proteins encoded by these genes are small proteins with signal peptides. IDI-2 protein is a cysteine-rich protein. IDI-2 and IDI-3 proteins display some similarity in a tryptophan-rich region.

scholarly journals Accelerated Cell Death in Podospora Autophagy Mutants

2005 ◽  
Vol 4 (11) ◽  
pp. 1765-1774 ◽  
Author(s):  
Bérangère Pinan-Lucarré ◽  
Axelle Balguerie ◽  
Corinne Clavé
Keyword(s):  
Cell Death ◽  
Fluorescent Protein ◽  
Protective Role ◽  
Podospora Anserina ◽  
Type Ii ◽  
Reaction Cell ◽  
Developmental Defects ◽  
A Cell ◽  
Green Fluorescent ◽  
Incompatibility Reaction

ABSTRACT Although autophagy is characteristic of type II programmed cell death (PCD), its role in cell death is currently debated. Both cell death-promoting and prosurvival roles of autophagy have been reported depending on the organism and the cell type. In filamentous fungi, a cell death reaction known as an incompatibility reaction occurs when cells of unlike genotype fuse. Cell death by incompatibility is characterized by a dramatic vacuolar enlargement and cell lysis. In Podospora anserina, autophagy is induced early during this cell death reaction. Cell death by incompatibility in Podospora is a model of type II PCD used here to assess the role of autophagy in this type of cell death. We have inactivated PaATG1, the Podospora ortholog of the Saccharomyces cerevisiae ATG1 gene involved in the early steps of autophagy in yeast. The ΔPaATG1 mutant displays developmental defects characteristic of abrogated autophagy in Podospora. Using the green fluorescent protein-PaATG8 autophagosome marker, we show that autophagy is abolished in this mutant. Neither cell death by incompatibility nor vacuolization are suppressed in ΔPaATG1 and ΔPaATG8 autophagy mutants, indicating that a vacuolar cell death reaction without autophagy occurs in Podospora. Our results thus provide a novel example of a type II PCD reaction in which autophagy is not the cause of cell death. In addition, we found that cell death is accelerated in ΔPaATG null mutants, suggesting that autophagy has a protective role in this type II PCD reaction.

scholarly journals The mod-A Suppressor of Nonallelic Heterokaryon Incompatibility in Podospora anserina Encodes a Proline-Rich Polypeptide Involved in Female Organ Formation

Genetics ◽  
1998 ◽  
Vol 149 (2) ◽  
pp. 915-926 ◽  
Author(s):  
Christian Barreau ◽  
Maya Iskandar ◽  
Gabriel Loubradou ◽  
Véronique Levallois ◽  
Joël Bégueret
Keyword(s):  
Protein Interactions ◽  
Cellular Differentiation ◽  
Growth Arrest ◽  
Podospora Anserina ◽  
The Self ◽  
Protein Protein Interactions ◽  
Vegetative Incompatibility ◽  
Binding Motifs ◽  
Reading Frame ◽  
Incompatibility Reaction

Abstract Vegetative incompatibility in fungi results from the control of heterokaryon formation by the genes present at het loci. Coexpression of antagonistic het genes in the same hyphae leads to a lethal process. In Podospora anserina, self-incompatible strains containing nonallelic incompatible genes in the same nucleus are inviable as the result of a growth arrest and a lytic process. Mutations in suppressor genes (mod genes) can restore the viability. These mod mutations also interfere with developmental processes, which suggests common steps between the incompatibility reaction and cellular differentiation. The mod-A locus, responsible for growth arrest in the self-incompatible strains, is also involved in the control of the development of female organs. The mod-A gene was isolated. An open reading frame 687 amino acids long was identified. The MOD-A-encoded polypeptide is rich in proline residues, which are clustered in a domain containing a motif that displays similarity to SH3-binding motifs, which are known to be involved in protein-protein interactions. Construction of a strain deleted for mod-A confirmed that the product of this gene involved in differentiation is a key regulator of growth arrest associated with vegetative incompatibility.

scholarly journals Molecular regulation of Snai2 in development and disease

2019 ◽  
Vol 132 (23) ◽  
Author(s):  
Wenhui Zhou ◽  
Kayla M. Gross ◽  
Charlotte Kuperwasser
Keyword(s):  
Transcription Factor ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Epithelial To Mesenchymal Transition ◽  
Zinc Finger Protein ◽  
Main Role ◽  
Biological Processes ◽  
Developmental Defects ◽  
Mesenchymal Transition ◽  
Damage Repair

ABSTRACT The transcription factor Snai2, encoded by the SNAI2 gene, is an evolutionarily conserved C2H2 zinc finger protein that orchestrates biological processes critical to tissue development and tumorigenesis. Initially characterized as a prototypical epithelial-to-mesenchymal transition (EMT) transcription factor, Snai2 has been shown more recently to participate in a wider variety of biological processes, including tumor metastasis, stem and/or progenitor cell biology, cellular differentiation, vascular remodeling and DNA damage repair. The main role of Snai2 in controlling such processes involves facilitating the epigenetic regulation of transcriptional programs, and, as such, its dysregulation manifests in developmental defects, disruption of tissue homeostasis, and other disease conditions. Here, we discuss our current understanding of the molecular mechanisms regulating Snai2 expression, abundance and activity. In addition, we outline how these mechanisms contribute to disease phenotypes or how they may impact rational therapeutic targeting of Snai2 dysregulation in human disease.

scholarly journals HET-E and HET-D Belong to a New Subfamily of WD40 Proteins Involved in Vegetative Incompatibility Specificity in the Fungus Podospora anserina

Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 71-81
Author(s):  
Eric Espagne ◽  
Pascale Balhadère ◽  
Marie-Louise Penin ◽  
Christian Barreau ◽  
Béatrice Turcq
Keyword(s):  
Genetic Difference ◽  
Podospora Anserina ◽  
Wild Type ◽  
Incompatible Interaction ◽  
Vegetative Incompatibility ◽  
Repeat Domain ◽  
Upper Face ◽  
E1a Gene ◽  
Type Strains ◽  
Wd40 Repeats

Abstract Vegetative incompatibility, which is very common in filamentous fungi, prevents a viable heterokaryotic cell from being formed by the fusion of filaments from two different wild-type strains. Such incompatibility is always the consequence of at least one genetic difference in specific genes (het genes). In Podospora anserina, alleles of the het-e and het-d loci control heterokaryon viability through genetic interactions with alleles of the unlinked het-c locus. The het-d2Y gene was isolated and shown to have strong similarity with the previously described het-e1A gene. Like the HET-E protein, the HET-D putative protein displayed a GTP-binding domain and seemed to require a minimal number of 11 WD40 repeats to be active in incompatibility. Apart from incompatibility specificity, no other function could be identified by disrupting the het-d gene. Sequence comparison of different het-e alleles suggested that het-e specificity is determined by the sequence of the WD40 repeat domain. In particular, the amino acids present on the upper face of the predicted β-propeller structure defined by this domain may confer the incompatible interaction specificity.

scholarly journals Identification of Six Loci in Which Mutations Partially Restore Peroxisome Biogenesis and/or Alleviate the Metabolic Defect of pex2 Mutants in Podospora

Genetics ◽  
2002 ◽  
Vol 161 (3) ◽  
pp. 1089-1099
Author(s):  
Gwenaël Ruprich-Robert ◽  
Véronique Berteaux-Lecellier ◽  
Denise Zickler ◽  
Arlette Panvier-Adoutte ◽  
Marguerite Picard
Keyword(s):  
Sole Carbon Source ◽  
Large Scale ◽  
Podospora Anserina ◽  
Developmental Defect ◽  
Dominant Allele ◽  
Peroxisome Biogenesis ◽  
Metabolic Defects ◽  
Metabolic Defect ◽  
Mutant Strains ◽  
Large Scale Screening

Abstract Peroxins (PEX) are proteins required for peroxisome biogenesis. Mutations in PEX genes cause lethal diseases in humans, metabolic defects in yeasts, and developmental disfunctions in plants and filamentous fungi. Here we describe the first large-scale screening for suppressors of a pex mutation. In Podospora anserina, pex2 mutants exhibit a metabolic defect [inability to grow on medium containing oleic acid (OA medium) as sole carbon source] and a developmental defect (inability to differentiate asci in homozygous crosses). Sixty-three mutations able to restore growth of pex2 mutants on OA medium have been analyzed. They fall in six loci (suo1 to suo6) and act as dominant, allele-nonspecific suppressors. Most suo mutations have pleiotropic effects in a pex2+ background: formation of unripe ascospores (all loci except suo5 and suo6), impaired growth on OA medium (all loci except suo4 and suo6), or sexual defects (suo4). Using immunofluorescence and GFP staining, we show that peroxisome biogenesis is partially restored along with a low level of ascus differentiation in pex2 mutant strains carrying either the suo5 or the suo6 mutations. The data are discussed with respect to β-oxidation of fatty acids, peroxisome biogenesis, and cell differentiation.

scholarly journals Loss of histone methyltransferase ASH1L in the developing mouse brain causes autistic-like behaviors

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yuen Gao ◽  
Natalia Duque-Wilckens ◽  
Mohammad B. Aljazi ◽  
Yan Wu ◽  
Adam J. Moeser ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mouse Brain ◽  
Molecular Mechanisms ◽  
Gene Mutations ◽  
Autism Spectrum ◽  
Normal Brain ◽  
Critical Function ◽  
Developmental Defects ◽  
Neurodevelopmental Disease ◽  
Developing Mouse Brain

AbstractAutism spectrum disorder (ASD) is a neurodevelopmental disease associated with various gene mutations. Recent genetic and clinical studies report that mutations of the epigenetic gene ASH1L are highly associated with human ASD and intellectual disability (ID). However, the causality and underlying molecular mechanisms linking ASH1L mutations to genesis of ASD/ID remain undetermined. Here we show loss of ASH1L in the developing mouse brain is sufficient to cause multiple developmental defects, core autistic-like behaviors, and impaired cognitive memory. Gene expression analyses uncover critical roles of ASH1L in regulating gene expression during neural cell development. Thus, our study establishes an ASD/ID mouse model revealing the critical function of an epigenetic factor ASH1L in normal brain development, a causality between Ash1L mutations and ASD/ID-like behaviors in mice, and potential molecular mechanisms linking Ash1L mutations to brain functional abnormalities.

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