scholarly journals Identification of a Hydrophobin Gene That is Developmentally Regulated in the Ectomycorrhizal Fungus Tricholoma terreum

2002 ◽  
Vol 68 (3) ◽  
pp. 1408-1413 ◽  
Author(s):  
Angela Mankel ◽  
Katrin Krause ◽  
Erika Kothe
Keyword(s):  
Transcriptional Control ◽  
Forest Ecology ◽  
Schizophyllum Commune ◽  
Aerial Mycelium ◽  
Ectomycorrhizal Fungus ◽  
Protein Accumulation ◽  
Transcriptional Level ◽  
Developmentally Regulated ◽  
Accumulation Pattern ◽  
Tricholoma Terreum

ABSTRACT The symbiosis between ectomycorrhizal fungi and trees is an essential part of forest ecology and depends entirely on the communication between the two partners for establishing and maintaining the relationship. The identification and characterization of differentially expressed genes is a step to identifying such signals and to understanding the regulation of this process. We determined the role of hydrophobins produced by Tricholoma terreum in mycorrhiza formation and hyphal development. A hydrophobin was purified from culture supernatant, and the corresponding gene was identified. The gene is expressed in aerial mycelium and in mycorrhiza. By using a heterologous antiserum directed against a hydrophobin found in the aerial mycelium of Schizophyllum commune, we detected a hydrophobin in the symbiosis between T. terreum and its native pine host Pinus sylvestris. The hydrophobin was found in aerial mycelium of the hyphal mantle and also in the Hartig net hyphae, which form the interface between both partners. Interestingly, this was not the case in the interaction of T. terreum with a host of low compatibility, the spruce Picea abies. The differential expression with respect to host was verified at the transcriptional level by competitive PCR. The differential protein accumulation pattern with respect to host compatibility seen by immunofluorescence staining can thus be attributed at least in part to transcriptional control of the hyd1 gene.

scholarly journals Homology-Dependent Silencing of the SC3 Gene in Schizophyllum commune

Genetics ◽  
1997 ◽  
Vol 147 (2) ◽  
pp. 589-596 ◽  
Author(s):  
Theo A Schuurs ◽  
Eveline A M Schaeffer ◽  
Joseph G H Wessels
Keyword(s):  
Gene Silencing ◽  
Genomic Dna ◽  
Type Strain ◽  
Cytosine Methylation ◽  
Wild Type Strain ◽  
Schizophyllum Commune ◽  
Southern Analysis ◽  
Transcriptional Level ◽  
Wild Type

After introduction of extra copies of the SC3 hydrophobin gene into a wild-type strain of Schizophyllum commune, gene silencing was observed acting on both endogenous and introduced SC3 genes in primary vegetative transformants. Nuclear run-on experiments indicated that silencing acted at the transcriptional level. Southern analysis revealed that cytosine methylation of genomic DNA occurred. Moreover, SC3 silencing was suppressed by exposure to 5-azacytidine during growth. After growth of SC3-suppressed colonies from homogenized mycelium or from colonies stored at 4°, SC3 transcription was restored. However, after prolonged growth SC3 silencing was again observed. Introduction of a promoterless SC3 fragment into wild type gave less SC3 silencing.

scholarly journals Polycombs and microRNA-223 regulate human granulopoiesis by transcriptional control of target gene expression

Blood ◽  
2012 ◽  
Vol 119 (17) ◽  
pp. 4034-4046 ◽  
Author(s):  
Giuseppe Zardo ◽  
Alberto Ciolfi ◽  
Laura Vian ◽  
Linda M. Starnes ◽  
Monia Billi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Sequences ◽  
Transcriptional Control ◽  
Transcriptional Level ◽  
Seed Region ◽  
Mrna Targets ◽  
Epigenetic Events ◽  
Evolutionarily Conserved ◽  
Lineage Decision ◽  
Chromatin Remodeling Complexes

Abstract Epigenetic modifications regulate developmental genes involved in stem cell identity and lineage choice. NFI-A is a posttranscriptional microRNA-223 (miR-223) target directing human hematopoietic progenitor lineage decision: NFI-A induction or silencing boosts erythropoiesis or granulopoiesis, respectively. Here we show that NFI-A promoter silencing, which allows granulopoiesis, is guaranteed by epigenetic events, including the resolution of opposing chromatin “bivalent domains,” hypermethylation, recruitment of polycomb (PcG)–RNAi complexes, and miR-223 promoter targeting activity. During granulopoiesis, miR-223 localizes inside the nucleus and targets the NFI-A promoter region containing PcGs binding sites and miR-223 complementary DNA sequences, evolutionarily conserved in mammalians. Remarkably, both the integrity of the PcGs-RNAi complex and DNA sequences matching the seed region of miR-223 are required to induce NFI-A transcriptional silencing. Moreover, ectopic miR-223 expression in human myeloid progenitors causes heterochromatic repression of NFI-A gene and channels granulopoiesis, whereas its stable knockdown produces the opposite effects. Our findings indicate that, besides the regulation of translation of mRNA targets, endogenous miRs can affect gene expression at the transcriptional level, functioning in a critical interface between chromatin remodeling complexes and the genome to direct fate lineage determination of hematopoietic progenitors.

scholarly journals Comparative analysis of plant isochorismate synthases reveals structural mechanisms underlying their distinct biochemical properties

2018 ◽  
Vol 38 (2) ◽  
Author(s):  
Shohei Yokoo ◽  
Seiya Inoue ◽  
Nana Suzuki ◽  
Naho Amakawa ◽  
Hidenori Matsui ◽  
...  
Keyword(s):  
Biochemical Properties ◽  
Stress Conditions ◽  
The Other ◽  
Protein Accumulation ◽  
Transcriptional Level ◽  
Multiple Sequence ◽  
Primary And Secondary Metabolites ◽  
Transit Peptides ◽  
Alignment Analysis ◽  
Structural Mechanisms

Isochorismate synthase (ICS) converts chorismate into isochorismate, a precursor of primary and secondary metabolites including salicylic acid (SA). SA plays important roles in responses to stress conditions in plants. Many studies have suggested that the function of plant ICSs is regulated at the transcriptional level. In Arabidopsis thaliana, the expression of AtICS1 is induced by stress conditions in parallel with SA synthesis, and AtICS1 is required for SA synthesis. In contrast, the expression of NtICS is not induced when SA synthesis is activated in tobacco, and it is unlikely to be involved in SA synthesis. Studies on the biochemical properties of plant ICSs are limited, compared with those on transcriptional regulation. We analyzed the biochemical properties of four plant ICSs: AtICS1, NtICS, NbICS from Nicotiana benthamiana, and OsICS from rice. Multiple sequence alignment analysis revealed that their primary structures were well conserved, and predicted key residues for ICS activity were almost completely conserved. However, AtICS1 showed much higher activity than the other ICSs when expressed in Escherichia coli and N. benthamiana leaves. Moreover, the levels of AtICS1 protein expression in N. benthamiana leaves were higher than the other ICSs. Construction and analysis of chimeras between AtICS1 and OsICS revealed that the putative chloroplast transit peptides (TPs) significantly affected the levels of protein accumulation in N. benthamiana leaves. Chimeric and point-mutation analyses revealed that Thr531, Ser537, and Ile550 of AtICS1 are essential for its high activity. These distinct biochemical properties of plant ICSs may suggest different roles in their respective plant species.

Specificity of accumulation and transmission of tomato spotted wilt virus (TSWV) in two genera, Frankliniella and Thrips (Thysanoptera: Thripidae)

2004 ◽  
Vol 94 (6) ◽  
pp. 501-507 ◽  
Author(s):  
T. Inoue ◽  
T. Sakurai ◽  
T. Murai ◽  
T. Maeda
Keyword(s):  
Tomato Spotted Wilt Virus ◽  
Virus Transmission ◽  
Leaf Disc ◽  
Enzyme Linked Immunosorbent Assay ◽  
Protein Accumulation ◽  
Accumulation Pattern ◽  
N Protein ◽  
Tomato Spotted Wilt ◽  
Wilt Virus ◽  
Elisa Titre

AbstractThe accumulation and transmission of tomato spotted wilt virus (TSWV) was examined in second instar larvae and adults of two thrips genera, Frankliniella and Thrips. The species tested were F. occidentalis (Pergande), F. intonsa (Trybom), T. tabaciLindeman, T. setosus Moulton, T. palmi Karny and T. hawaiiensis (Morgan). In a standard petunia leaf disc assay, the efficiencies of TSWV transmission by two species of Frankliniella were higher than those of any Thrips species in the adult stage. A triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA) showed that large amounts of the TSWV-nucleocapsid (N) protein were present in the ELISA-positive larvae of each species, with the exception of T. palmi. The ELISA titre of and the proportion of virus-infected individuals of the two Frankliniella species increased or did not significantly change from the larval to the adult stages, whereas those of the four Thrips species decreased significantly. These results show that the specificity of virus transmission by adult thrips is probably affected by the amount of viral N protein accumulation in the adults and that the accumulation pattern from the larval to the adult stages is in between the two genera tested in the present study.

Amino acid transporter expression and localisation studies in pea (Pisum sativum)

2007 ◽  
Vol 34 (11) ◽  
pp. 1019 ◽  
Author(s):  
Mechthild Tegeder ◽  
Qiumin Tan ◽  
Aleel K. Grennan ◽  
John W. Patrick
Keyword(s):  
Amino Acid ◽  
Pisum Sativum ◽  
Storage Protein ◽  
Expression Patterns ◽  
Phloem Loading ◽  
Transfer Cells ◽  
Protein Accumulation ◽  
Developmentally Regulated ◽  
And Storage ◽  
Seed Coats

Expression of the amino acid permeases PsAAP1 and PsAAP2 was analysed in developing pea (Pisum sativum L.) plants. Both transporters were expressed in seed coats and cotyledon epidermal transfer cells and storage parenchyma cells. AAP expression is developmentally regulated and coincides with the onset of storage protein synthesis. Nitrogen was shown to induce AAP expression and AAP transcript levels were upregulated during the photoperiod. Analysis of Arabidopsis thaliana AAP1 promoter activity in pea, using promoter-β-glucuronidase (promotor-GUS) studies, revealed targeting of GUS to seed coats and cotyledon epidermal transfer cells. Expression was found in the nutritious endosperm during the early stages of seed development, whereas GUS staining in embryos was detected from the heart stage onward. In addition, AAP1 expression was observed in the phloem throughout the plant. This finding equally applied to PsAAP1 expression as shown by in situ mRNA hybridisation, which also demonstrated that PsAAP1 expression was localised to companion cells. Overall, PsAAP1 expression patterns and cellular localisation point to a function of the transporter in phloem loading of amino acids for translocation to sinks and in seed loading for development and storage protein accumulation.

scholarly journals Transcriptional Regulation of sitABCD of Salmonella enterica Serovar Typhimurium by MntR and Fur

2005 ◽  
Vol 187 (3) ◽  
pp. 912-922 ◽  
Author(s):  
Jack S. Ikeda ◽  
Anuradha Janakiraman ◽  
David G. Kehres ◽  
Michael E. Maguire ◽  
James M. Slauch
Keyword(s):  
Transcriptional Regulation ◽  
Binding Sites ◽  
Transcriptional Repression ◽  
Salmonella Enterica ◽  
Transcriptional Control ◽  
Natural Resistance ◽  
Transport Systems ◽  
Transcriptional Level ◽  
Promoter Regions ◽  
Serovar Typhimurium

ABSTRACT Salmonella enterica serovar Typhimurium has two manganese transport systems, MntH and SitABCD. MntH is a bacterial homolog of the eukaryotic natural resistance-associated macrophage protein 1 (Nramp1), and SitABCD is an ABC-type transporter. Previously we showed that mntH is negatively controlled at the transcriptional level by the trans-acting regulatory factors, MntR and Fur. In this study, we examined the transcriptional regulation of sitABCD and compared it to the transcriptional regulation of mntH by constructing lacZ fusions to the promoter regions with and without mutations in putative MntR and/or Fur binding sites. The presence of Mn caused transcriptional repression of the sitABCD and mntH promoters primarily via MntR, but Fur was also capable of some repression in response to Mn. Likewise, Fe in the medium repressed transcription of both sit and mntH primarily via Fur, although MntR was also involved in this response. Transcriptional control by MntR and Fur was disrupted by site-specific mutations in the putative MntR and Fur binding sites, respectively. Transcription of the sit operon was also affected by the oxygen level and growth phase, but the increased expression observed under high oxygen conditions and higher cell densities is consistent with decreased availability of metals required for repression by the metalloregulatory proteins.

scholarly journals Nuclease activities and cell death processes associated with the development of surface cultures of Streptomyces antibioticus ETH 7451

Microbiology ◽  
2002 ◽  
Vol 148 (2) ◽  
pp. 405-412 ◽  
Author(s):  
Marisol Fernández ◽  
Jesús Sánchez
Keyword(s):  
Cell Death ◽  
Aerial Mycelium ◽  
Dna Degradation ◽  
Death Process ◽  
Chromosomal Dna ◽  
Developmentally Regulated ◽  
Streptomyces Antibioticus ◽  
Viability Assay ◽  
Green Fluorescent ◽  
Dying Cells

The presence and significance of developmentally regulated nucleases in Streptomyces antibioticus ETH 7451 has been studied in relation to the lytic processes occurring during differentiation. The cell-death processes have been followed in surface cultures by a propidium iodide viability assay. This has allowed the visualization of dead (membrane-damaged, red fluorescent) and live (membrane-intact, green fluorescent) mycelium during development, and has facilitated the analysis of the role of nucleases in these processes. A parallel activity-gel analysis showed the appearance of 20–22 kDa, 34 kDa and 44 kDa nucleases, the latter appearing only when aerial mycelium is formed. The appearance of these nucleases shows a remarkable correlation with the death process of the mycelium during differentiation and with chromosomal DNA degradation. The 20–22 kDa enzymes are possibly related to the lytic phenomena taking place in the vegetative substrate mycelium before the emergence of the reproductive aerial mycelium, whereas the function of the 44 kDa nuclease seems to be related to the sporulation step. The 20–22 kDa nucleases require Ca2+ for activity and are inhibited by Zn2+. The nucleases are loosely bound to the cell wall from where they can be liberated by simple washing. Conceivably, these enzymes work together and co-ordinate to achieve an efficient hydrolysis of DNA from dying cells. The results show that the biochemical reactions related with the lytic DNA degradation during the programmed cell death are notably conserved in Streptomyces. Some of the features of the process and the biochemical characteristics of the enzymes involved are analogous to those taking place during the DNA fragmentation processes in eukaryotic apoptotic cells.

Regulation of human IGF-II transcription in fetal and adult tissues

Development ◽  
1987 ◽  
Vol 101 (4) ◽  
pp. 793-803
Author(s):  
P.N. Schofield ◽  
V.E. Tate
Keyword(s):  
Transcriptional Control ◽  
Cell Multiplication ◽  
Mammalian Development ◽  
Single Chain ◽  
Developmentally Regulated ◽  
Major Species ◽  
Steady State Levels ◽  
Cell Growth And Differentiation ◽  
Fetal Organs

The insulin-like growth factors are single-chain polypeptides which promote cell multiplication in vitro. Their role in mammalian development is uncertain, although they have been implicated as modulators of cell growth and differentiation. We present evidence that the human IGF-II gene has at least two promoters, and their expression may be developmentally controlled in the liver. Most of the IGF-II transcripts in the fetal organs examined are derived from a promoter which is different to that used for most adult liver IGF-II mRNAs. Steady-state levels of IGF-II transcripts are seen to be dramatically reduced in organs of adult rather than fetal origin. This observation is apparently not linked to promoter usage and therefore suggests a second level of transcriptional control. In addition, we show that an alternative splicing event at an intron/exon boundary, which results in an mRNA with an altered coding potential, is not developmentally regulated. This variant IGF-II mRNA is coexpressed with the major species of IGF-II at a low, but constant, ratio in all fetal and adult organs examined.

Two divergently transcribed genes of Dictyostelium discoideum are cyclic AMP-inducible and coregulated during development

1987 ◽  
Vol 7 (12) ◽  
pp. 4482-4489
Author(s):  
D M Driscoll ◽  
J G Williams
Keyword(s):  
Cyclic Amp ◽  
Nucleic Acids ◽  
Dictyostelium Discoideum ◽  
Dna Sequences ◽  
Intergenic Region ◽  
Cysteine Proteinase ◽  
Transcriptional Level ◽  
Dependent Manner ◽  
Developmentally Regulated ◽  
Reading Frame

The cysteine proteinase 1 (CP1) gene of Dictyostelium discoideum encodes a developmentally regulated sulfhydryl proteinase. We characterized the DNA sequences upstream of the CP1 gene and found a second developmentally regulated gene, which we term DG17. The translational open reading frame of the DG17 gene encoded a 458-amino-acid cysteine- and lysine-rich protein of unknown function. In several regions, the cysteine and lysine residues were arranged in a manner characteristic of the zinc-binding domains found in proteins which interact with nucleic acids. During normal development, the DG17 and CP1 genes are coordinately activated late in aggregation. The addition of exogenous cyclic AMP (cAMP) induced the premature expression of both mRNAs. By measuring the rate of specific mRNA synthesis in isolated nuclei, we showed that cAMP acted at the transcriptional level to activate both genes. The two genes were separated by 910 nucleotides and were divergently transcribed. The intergenic region was predominantly composed of A + T residues except for four short G-rich regions. These sequences coincided with the positions of four nuclease-hypersensitive sites, which appear during aggregation when the DG17 and CP1 genes are transcribed (J. Pavlovic, E. Banz, and R. W. Parish, Nucleic Acids Res. 14:8703-8722, 1986). Two of the G-rich regions formed the core of two almost identical 80-nucleotide repeats located 220 and 320 nucleotides upstream of the CP1 gene. Using the Dictyostelium transformation system, we showed that a restriction fragment containing the intergenic region was capable of directing bidirectional transcription in a cAMP-dependent manner.

Specific regulation of transcription of the discoidin gene family in Dictyostelium discoideum

1985 ◽  
Vol 5 (5) ◽  
pp. 984-990
Author(s):  
S Alexander ◽  
T M Shinnick
Keyword(s):  
Gene Family ◽  
Dictyostelium Discoideum ◽  
Developmental Expression ◽  
Transcriptional Level ◽  
Regulation Of Transcription ◽  
Developmentally Regulated ◽  
The Family ◽  
Lectin Genes ◽  
Regulatory Loci ◽  
Specific Regulation

Dictyostelium discoideum strains that carry the dis mutations fail to express the family of developmentally regulated discoidin lectin genes during morphogenesis. We show here that this absence of discoidin lectin expression is due to the failure to transcribe the discoidin genes. Furthermore, the dis mutations appear to affect only discoidin expression and not the expression of other proteins during development, as assessed by a two-dimensional gel analysis of pulse-labeled proteins and by the accumulation of developmentally regulated enzymes. The dis mutations appear to define trans-acting regulatory loci, the products of which act at the transcriptional level to control specifically the developmental expression of the discoidin gene family.

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