scholarly journals Glucose Signaling Pathway and Growth Conditions Regulate Gene Expression in Retrotransposon Ty2

2009 ◽  
Vol 64 (7-8) ◽  
pp. 526-532 ◽  
Author(s):  
Sezai Türkel ◽  
Özgür Bayram ◽  
Elif Arık
Keyword(s):  
Gene Expression ◽  
Growth Conditions ◽  
Glucose Sensors ◽  
Yeast Cells ◽  
Growth Stages ◽  
Regulate Gene Expression ◽  
Glucose Signaling ◽  
Yeast Cultures ◽  
Membrane Bound ◽  
High Level

Gene expression in the yeast retrotransposon Ty2 is regulated at transcriptional and translational levels. In this study, we have shown that the transcription of Ty2 is partially dependent on the membrane-bound glucose sensors Gpr1p and Mth1p in Saccharomyces cerevisiae. Transcription of Ty2 decreased approx. 3-fold in the gpr1, mth1 yeast mutant. Moreover, our results revealed that the transcription of Ty2 fluctuates during the growth stages of S. cerevisae. Both transcription and the frameshift rate of Ty2 rapidly dropped when the stationary stage yeast cells were inoculated into fresh medium. There was an instant activation of Ty2 transcription and a high level expression during the entire logarithmic stage of yeast growth. However, the transcription of Ty2 decreased 2-fold when the yeast cultures entered the stationary stage. The frameshift rate in Ty2 also varied depending on the growth conditions. The highest frameshift level was observed during the mid-logarithmic stage. It decreased up to 2-fold during the stationary stage. Furthermore, we have found that the frameshift rate of Ty2 diminished at least 5-fold in slowly growing yeasts. These results indicate that the transcription and the frameshift efficiency are coordinately regulated in the retrotransposon Ty2 depending on the growth conditions of S. cerevisiae.

scholarly journals Analysis of Genes That Encode DtxR-Like Transcriptional Regulators in Pathogenic and Saprophytic Corynebacterial Species

2004 ◽  
Vol 72 (4) ◽  
pp. 1885-1895 ◽  
Author(s):  
Diana Marra Oram ◽  
Ana Avdalovic ◽  
Randall K. Holmes
Keyword(s):  
Gene Expression ◽  
Metal Binding ◽  
Regulatory Protein ◽  
Transcriptional Regulators ◽  
Chromosomal Dna ◽  
Regulate Gene Expression ◽  
Protein Levels ◽  
Diphtheria Toxin Repressor ◽  
Conserved Region ◽  
High Level

ABSTRACT Metal-dependent transcriptional regulators of the diphtheria toxin repressor (DtxR) family have been identified in a wide variety of bacterial genera, where they control gene expression in response to one of two metal ions, Fe2+ or Mn2+. DtxR of Corynebacterium diphtheriae is the best characterized of these important metal-dependent regulators. The genus Corynebacterium includes many phenotypically diverse species, and the prevalence of DtxR-like regulators within the genus is unknown. We assayed chromosomal DNA from 42 different corynebacterial isolates, representing 33 different species, for the presence of a highly conserved region of the dtxR gene that encodes the DNA-binding helix-turn-helix motif and metal-binding site 1 within domains 1 and 2 of DtxR. The chromosome of all of the isolates contained this conserved region of dtxR, and DNA sequencing revealed a high level of nucleotide sequence conservation within this region in all of the corynebacterial species (ranging from 62 to 100% identity and averaging 70% identity with the dtxR prototype). The level of identity was even greater for the predicted protein sequences encoded by the dtxR-like genes, ranging from 81 to 100% identity and averaging 91% identity with DtxR. Using a DtxR-specific antiserum we confirmed the presence of a DtxR-like protein in extracts of most of the corynebacterial isolates and determined the precise amount of DtxR per cell in C. diphtheriae. The high level of identity at both DNA and protein levels suggests that all of the isolates tested encode a functional DtxR-like Fe2+-activated regulatory protein that can bind homologs of the DtxR operator and regulate gene expression in response to iron.

scholarly journals Poaceae Orthologs of Rice OsSGL, DUF1645 Domain-Containing Genes, Positively Regulate Drought Tolerance, Grain Length and Weight in Rice

2020 ◽  
Author(s):  
Kai Liu ◽  
Mingjuan Li ◽  
Bin Zhang ◽  
Yanchun Cui ◽  
Xuming Yin ◽  
...  
Keyword(s):  
Drought Stress ◽  
Stress Tolerance ◽  
Molecular Mechanisms ◽  
Normal Growth ◽  
Growth Conditions ◽  
Growth Stages ◽  
Grain Length ◽  
Drought Stress Tolerance ◽  
High Level ◽  
Seed Setting Percentage

Abstract BackgroundGrain yield is a polygenic trait influenced by environmental and genetic interactions at all growth stages of the cereal plant. However, the molecular mechanisms responsible for coordinating the trade-off or cross-talk between these traits remain elusive.ResultsWe characterized the hitherto unknown function of four STRESS_tolerance and GRAIN_LENGTH (OsSGL) Poaceae ortholog genes, all encoding DUF1645 domain-containing proteins, in simultaneous regulation of grain length, grain weight, and drought stress-tolerance in rice. In normal growth conditions, the four ortholog genes were mainly expressed in the developing roots and panicles of the corresponding species. Over-expressing or heterologous high-level expressing Poaceae OsSGL ortholog genes conferred remarkably increased grain length, weight, and seed setting percentage, as well as significantly improved drought-stress tolerance in transgenic rice. Microscopical analysis also showed that the transgene expression promoted cell division and development. RNA-seq and qRT-PCR analyses revealed 73.8% (18,711) overlapped DEGs in all transgenic plants. Moreover, GO and KEGG analyses of different comparisons revealed that the key DEGs participating in drought stress-response belonged to hormone (especially auxin and cytokinin) pathways, and signaling processes were apparently affected in the young panicles. ConclusionTogether, these results suggest the four OsSGL orthologs perform a conserved function in regulating stress-tolerance and cell growth by acting via a hormone biosynthesis and signaling pathway. It may also induce a strategy for tailor-made crop yield improvement.

scholarly journals FORMATION OF AUXIN IN YEAST CULTURES

1941 ◽  
Vol 24 (6) ◽  
pp. 765-769 ◽  
Author(s):  
True W. Robinson ◽  
T. J. B. Stier
Keyword(s):  
Culture Media ◽  
Growth Conditions ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Yeast Cells ◽  
Cell Multiplication ◽  
Inverse Relation ◽  
Hydrogen Ion Concentration ◽  
Protein Carrier ◽  
Yeast Cultures

We have found far more auxin in the culture media of bakers' yeast than was obtained by Kögl and Kostermans from the cells themselves. The production of auxin by yeast cells resembles the formation observed in other organisms such as Rhizopus and Rhizobium which also form auxins in their culture media. The auxin yield was found to increase with the concentration of sucrose and to decrease with the concentration of peptone. An inverse relation with the rate of cell multiplication was observed. Enlarged and elongated cells appeared only in those media which contained considerable amounts of auxin. The total auxin yield in the various cultures was found to be directly proportional, below pH 5, to the hydrogen ion concentration. Thus, it was proposed that certain growth conditions favor the breakage of the link between auxin and its protein carrier (Skoog and Thimann) 1940) and consequently accelerate the rate of excretion of auxin into the growth medium.

scholarly journals Two Functionally Distinct Regions Upstream of thecbbI Operon of Rhodobacter sphaeroides Regulate Gene Expression

1998 ◽  
Vol 180 (18) ◽  
pp. 4903-4911 ◽  
Author(s):  
James M. Dubbs ◽  
F. Robert Tabita
Keyword(s):  
Gene Expression ◽  
Rhodobacter Sphaeroides ◽  
Promoter Activity ◽  
Growth Conditions ◽  
Upstream Sequence ◽  
Normal Pattern ◽  
Transcription Start ◽  
Regulate Gene Expression ◽  
Low Levels ◽  
Regulate Gene

ABSTRACT A number ofcbbFI ::lacZ translational fusion plasmids containing various lengths of sequence 5′ to the form I (cbbI ) Calvin-Benson-Bassham cycle operon (cbbFIcbbPIcbbAIcbbLIcbbSI ) of Rhodobacter sphaeroides were constructed. Expression of β-galactosidase was monitored under a variety of growth conditions. It was found that 103 bp of sequence upstream of thecbbFI transcription start was sufficient to confer low levels of regulated cbbI promoter expression; this activity was dependent on the presence of an intactcbbR gene. Additionally, R. sphaeroidesCbbR was shown to bind to the region between 9 and 100 bp 5′ to thecbbFI transcription start. Inclusion of an additional upstream sequence, from 280 to 636 bp 5′ tocbbFI , resulted in a significant increase in regulated cbbI promoter expression under all growth conditions tested. A 50-bp region responsible for the majority of this increase occurs between 280 and 330 bp 5′ tocbbFI . The additional 306 bp of upstream sequence from 330 to 636 bp also appears to play a positive regulatory role. A 4-bp deletion 281 to 284 bp 5′ to cbbFI significantly reduced cbbI expression while the proper regulatory pattern was retained. These studies provide evidence for the presence of two functionally distinct regions of thecbbI promoter, with the distal domain providing significant regulated promoter activity that adheres to the normal pattern of expression.

Mutational analysis of human heat-shock transcription factor 1 reveals a regulatory role for oligomerization in DNA-binding specificity

2009 ◽  
Vol 424 (2) ◽  
pp. 253-261 ◽  
Author(s):  
Yukiko Takemori ◽  
Yasuaki Enoki ◽  
Noritaka Yamamoto ◽  
Yo Fukai ◽  
Kaori Adachi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Heat Shock ◽  
Dna Binding ◽  
Binding Domain ◽  
Heat Shock Transcription Factor ◽  
Yeast Cells ◽  
Dna Binding Domain ◽  
Regulate Gene Expression ◽  
Regulate Gene

HSF (heat-shock transcription factor) trimers bind to the HSE (heat-shock element) regulatory sequence of target genes and regulate gene expression. A typical HSE consists of at least three contiguous inverted repeats of the 5-bp sequence nGAAn. Yeast HSF is able to recognize discontinuous HSEs that contain gaps in the array of the nGAAn sequence; however, hHSF1 (human HSF1) fails to recognize such sites in vitro, in yeast and in HeLa cells. In the present study, we isolated suppressors of the temperature-sensitive growth defect of hHSF1-expressing yeast cells. Intragenic suppressors contained amino acid substitutions in the DNA-binding domain of hHSF1 that enabled hHSF1 to regulate the transcription of genes containing discontinuous HSEs. The substitutions facilitated hHSF1 oligomerization, suggesting that the DNA-binding domain is important for this conformational change. Furthermore, other oligomerization-prone derivatives of hHSF1 were capable of recognizing discontinuous HSEs. These results suggest that modulation of oligomerization is important for the HSE specificity of hHSF1 and imply that hHSF1 possesses the ability to bind to and regulate gene expression via various types of HSEs in diverse cellular processes.

scholarly journals Assembly and regulation of the yeast vacuolar H(+)-ATPase

2000 ◽  
Vol 203 (1) ◽  
pp. 81-87 ◽  
Author(s):  
P.M. Kane ◽  
K.J. Parra
Keyword(s):  
Carbon Source ◽  
Structural Changes ◽  
Growth Conditions ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Term Basis ◽  
Membrane Bound ◽  
Dynamic Structures

The yeast vacuolar H(+)-ATPase (V-ATPase) consists of a complex of peripheral subunits containing the ATP binding sites, termed the V(1) sector, attached to a complex of membrane subunits containing the proton pore, termed the V(o) sector. Interaction between the V(1) and V(o) sectors is essential for ATP-driven proton transport, and this interaction is manipulated in vivo as a means of regulating V-ATPase activity. When yeast (Saccharomyces cerevisiae) cells are deprived of glucose for as little as 5 min, up to 75% of the assembled V-ATPase complexes are disassembled into cytoplasmic V(1) sectors and membrane-bound V(o) sectors. Remarkably, this disassembly is completely reversible. Restoration of glucose to the growth medium results in quantitative reassembly of the disassembled complexes in as little as 5 min, even in the absence of any new protein synthesis. Cells also appear to regulate the extent of V(1)V(o) assembly on a long-term basis. Yeast cells grown for extended periods in a poor carbon source contain a high proportion of free V(1) and V(o) sectors, and these sectors remain poised for reassembly when growth conditions improve. Parallel experiments on the Manduca sexta V-ATPase suggest that reversible disassembly may be a general regulatory mechanism for V-ATPases. These results imply that V-ATPases are surprisingly dynamic structures, and their unique ‘regulated instability’ raises a number of interesting physiological and structural questions. How are extracellular conditions such as carbon source communicated to V-ATPase complexes present on intracellular membranes? How are such major structural changes in the V-ATPase generated and how are V(1) sectors ‘silenced’ in vivo to prevent unproductive hydrolysis of cytoplasmic ATP by the dissociated enzyme? We are addressing these questions using a combination of genetic and biochemical approaches.

scholarly journals Two membrane-bound transcription factors regulate expression of various type-IV-pili surface structures in Sulfolobus acidocaldarius

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6459 ◽  
Author(s):  
Lisa Franziska Bischof ◽  
Maria Florencia Haurat ◽  
Sonja-Verena Albers
Keyword(s):  
Gene Expression ◽  
Biochemical Characterization ◽  
Type Iv Pili ◽  
Regulate Gene Expression ◽  
Promoter Sequences ◽  
Type Iv ◽  
Membrane Bound ◽  
Filament Protein ◽  
Regulatory Connection

In Archaea and Bacteria, gene expression is tightly regulated in response to environmental stimuli. In the thermoacidophilic crenarchaeon Sulfolobus acidocaldarius nutrient limitation induces expression of the archaellum, the archaeal motility structure. This expression is orchestrated by a complex hierarchical network of positive and negative regulators—the archaellum regulatory network (arn). The membrane-bound one-component system ArnR and its paralog ArnR1 were recently described as main activators of archaellum expression in S. acidocaldarius. They regulate gene expression of the archaellum operon by targeting the promoter of flaB, encoding the archaellum filament protein. Here we describe a strategy for the isolation and biochemical characterization of these two archaellum regulators. Both regulators are capable of forming oligomers and are phosphorylated by the Ser/Thr kinase ArnC. Apart from binding to pflaB, ArnR but not ArnR1 bound to promoter sequences of aapF and upsX, which encode components of the archaeal adhesive pilus and UV-inducible pili system, demonstrating a regulatory connection between different surface appendages of S. acidocaldarius.

scholarly journals Std1 and Mth1 Proteins Interact with the Glucose Sensors To Control Glucose-Regulated Gene Expression in Saccharomyces cerevisiae

1999 ◽  
Vol 19 (7) ◽  
pp. 4561-4571 ◽  
Author(s):  
Martin C. Schmidt ◽  
Rhonda R. McCartney ◽  
Xudong Zhang ◽  
Tommy S. Tillman ◽  
Harry Solimeo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fluorescent Protein ◽  
Glucose Sensing ◽  
Glucose Sensors ◽  
Growth Defect ◽  
Cell Periphery ◽  
Hexose Transporter ◽  
Glucose Signaling ◽  
Green Fluorescent ◽  
Regulated Gene Expression

ABSTRACT The Std1 protein modulates the expression of glucose-regulated genes, but its exact molecular role in this process is unclear. A two-hybrid screen for Std1-interacting proteins identified the hydrophilic C-terminal domains of the glucose sensors, Snf3 and Rgt2. The homologue of Std1, Mth1, behaves differently from Std1 in this assay by interacting with Snf3 but not Rgt2. Genetic interactions between STD1, MTH1, SNF3, andRGT2 suggest that the glucose signaling is mediated, at least in part, through interactions of the products of these four genes. Mutations in MTH1 can suppress the raffinose growth defect of a snf3 mutant as well as the glucose fermentation defect present in cells lacking both glucose sensors (snf3 rgt2). Genetic suppression by mutations in MTH1 is likely to be due to the increased and unregulated expression of hexose transporter genes. In media lacking glucose or with low levels of glucose, the hexose transporter genes are subject to repression by a mechanism that requires the Std1 and Mth1 proteins. An additional mechanism for glucose sensing must exist since a strain lacking all four genes (snf3 rgt2 std1 mth1) is still able to regulateSUC2 gene expression in response to changes in glucose concentration. Finally, studies with green fluorescent protein fusions indicate that Std1 is localized to the cell periphery and the cell nucleus, supporting the idea that it may transduce signals from the plasma membrane to the nucleus.

Application of anti-listerial bacteriocins: monitoring enterocin expression by multiplex relative reverse transcription–PCR

2012 ◽  
Vol 40 (6) ◽  
pp. 1544-1548 ◽  
Author(s):  
D. Ross Williams ◽  
Panagiotis Chanos
Keyword(s):  
Gene Expression ◽  
Reverse Transcription ◽  
Enterococcus Faecium ◽  
Growth Conditions ◽  
High Level Expression ◽  
Fermentation Conditions ◽  
Reverse Transcription Pcr ◽  
Food Borne ◽  
High Level

Listeriosis is a deadly food-borne disease, and its incidence may be limited through the biotechnological exploitation of a number of anti-listerial biocontrol agents. The most widely used of these agents are bacteriocins and the Class II enterocins are characterized by their activity against Listeria. Enterocins are primarily produced by enterococci, particularly Enterococcus faecium and many strains have been described, often encoding multiple bacteriocins. The use of these strains in food will require that they are free of virulence functions and that they exhibit a high level expression of anti-listerial enterocins in fermentation conditions. Multiplex relative RT (reverse transcription)–PCR is a technique that is useful in the discovery of advantageous expression characteristics among enterocin-producing strains. It allows the levels of individual enterocin gene expression to be monitored and determination of how expression is altered under different growth conditions.

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