scholarly journals gerR, a Novel ger Operon Involved in l-Alanine- and Inosine-Initiated Germination of Bacillus cereus ATCC 14579

2005 ◽  
Vol 71 (2) ◽  
pp. 774-781 ◽  
Author(s):  
Luc M. Hornstra ◽  
Ynte P. de Vries ◽  
Willem M. de Vos ◽  
Tjakko Abee ◽  
Marjon H. J. Wells-Bennik
Keyword(s):  
High Pressure ◽  
Bacillus Cereus ◽  
Parental Strain ◽  
Essential Role ◽  
Insertional Mutagenesis ◽  
The Other ◽  
Receptor Complex ◽  
Germination Response ◽  
Mutant Strains

ABSTRACT Bacillus cereus endospores germinate in response to particular nutrients. Spores are able to sense these nutrients in the environment by receptors encoded by the gerA family of operons. Analysis of the Bacillus cereus ATCC 14579 genome revealed seven gerA family homologues. Using a transposon Tn917-based insertional mutagenesis approach followed by an enrichment procedure to select for l-alanine-induced germination mutants, we isolated a mutant with a defect in the l-alanine germination pathway. The transposon disrupted the last gene of a tricistronic gerA family operon, designated gerR, with the order gerRA, gerRC, gerRB. A second mutant was created by insertion of pMUTIN4 in gerRC. Both mutants showed the same phenotype for nutrient-induced germination. Spores of the gerR mutant strains were blocked in their l-alanine-initiated germination pathway and showed a delayed inosine-induced germination response. Apparently, germination mediated by l-alanine and inosine cannot be compensated for completely by the other germinant receptors, and this points towards an essential role of the gerR-encoded receptor in the receptor complex. In food products, spores of the mutant strains showed a reduced germination response compared to spores of the parental strain. High-pressure-initiated germination was not affected by the gerR mutations, as experiments with 100 and 550 MPa showed no difference with spores of the parental strain.

scholarly journals Role of Germinant Receptors in Caco-2 Cell-Initiated Germination of Bacillus cereus ATCC 14579 Endospores

2008 ◽  
Vol 75 (4) ◽  
pp. 1201-1203 ◽  
Author(s):  
Luc M. Hornstra ◽  
Menno van der Voort ◽  
Lucas M. Wijnands ◽  
Petra J. Roubos-van den Hil ◽  
Tjakko Abee
Keyword(s):  
Bacillus Cereus ◽  
Germination Response ◽  
Mutant Strains

ABSTRACT Spores obtained from Bacillus cereus ATCC 14579 and mutant strains lacking each of seven germinant receptor operons were exposed to differentiated Caco-2 cells and monitored for germination. Spores of the gerI and gerL mutants showed a reduced germination response, pointing to a role for these receptors in Caco-2-induced germination.

scholarly journals Characterization of Germination Receptors of Bacillus cereus ATCC 14579

2006 ◽  
Vol 72 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Luc M. Hornstra ◽  
Ynte P. de Vries ◽  
Marjon H. J. Wells-Bennik ◽  
Willem M. de Vos ◽  
Tjakko Abee
Keyword(s):  
Amino Acids ◽  
Bacillus Cereus ◽  
Signaling Pathway ◽  
The Other ◽  
Germination Response

ABSTRACT Specific amino acids, purine ribonucleosides, or a combination of the two is required for efficient germination of endospores of Bacillus cereus ATCC 14579. A survey including 20 different amino acids showed that l-alanine, l-cysteine, l-threonine, and l-glutamine are capable of initiating the germination of endospores of B. cereus ATCC 14579. In addition, the purine ribonucleosides inosine and adenosine can trigger germination of the spores. Advanced annotation of the B. cereus ATCC 14579 genome revealed the presence of seven putative germination (ger) operons, termed gerG, gerI, gerK, gerL, gerQ, gerR, and gerS. To determine the role of the encoded putative receptors in nutrient-induced germination, disruption mutants were constructed by the insertion of pMUTIN4 into each of the seven operons. Four of the seven mutants were affected in the germination response to amino acids or purine ribonucleosides, whereas no phenotype could be attributed to the mutants with disrupted gerK, gerL, and gerS loci. The strain with a disrupted gerR operon was severely hampered in the ability to germinate: germination occurred in response to l-glutamine but not in the presence of any of the other amino acids tested. The gerG mutant showed significantly reduced l-glutamine-induced germination, which points to a role of this receptor in the l-glutamine germination signaling pathway. gerR, gerI, and gerQ mutants showed reduced germination rates in the presence of inosine, suggesting a role for these operons in ribonucleoside signaling. Efficient germination by the combination of l-glutamine and inosine was shown to involve the gerG and gerI operons, since the germination of mutants lacking either one of these receptors was significantly reduced. Germination triggered by the combination of l-phenylalanine and inosine was lost in the gerI mutant, indicating that both molecules are effective at the GerI receptor.

The Gastronomy of the Eye

2020 ◽  
pp. 175-198
Author(s):  
Vrushali Dhage
Keyword(s):  
Essential Role ◽  
Historical Perspective ◽  
Smart Cities ◽  
Methodological Approach ◽  
Economic Liberalization ◽  
The Other ◽  
Works Of Art

Works of art can be read at various levels: from being objects of simple retinal pleasure to the other extreme of being significant critical statements of their time. This chapter aims to strike a cerebral dialogue through the works of art. The current study shall consider the latter function of art and analyze the methods in which contemporary Indian artists have made attempts to provide a critique of the early initiatives towards developing Delhi and Mumbai as ‘smart cities'. The review of works from India concludes the essential role of infrastructural projects and envisioned spaces built in the era of economic liberalization. The study aims at drawing a methodological approach, with an art historical perspective, with the artists analysing and translating the urban experiential phenomenon, into artworks.

scholarly journals RNA polymerase II plays an active role in the formation of gene loops through the Rpb4 subunit

2019 ◽  
Vol 47 (17) ◽  
pp. 8975-8987 ◽  
Author(s):  
Paula Allepuz-Fuster ◽  
Michael J O’Brien ◽  
Noelia González-Polo ◽  
Bianca Pereira ◽  
Zuzer Dhoondia ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Essential Role ◽  
Transcription Termination ◽  
Active Role ◽  
The Other ◽  
Loop Formation ◽  
Direct Role

AbstractGene loops are formed by the interaction of initiation and termination factors occupying the distal ends of a gene during transcription. RNAPII is believed to affect gene looping indirectly owing to its essential role in transcription. The results presented here, however, demonstrate a direct role of RNAPII in gene looping through the Rpb4 subunit. 3C analysis revealed that gene looping is abolished in the rpb4Δ mutant. In contrast to the other looping-defective mutants, rpb4Δ cells do not exhibit a transcription termination defect. RPB4 overexpression, however, rescued the transcription termination and gene looping defect of sua7-1, a mutant of TFIIB. Furthermore, RPB4 overexpression rescued the ssu72-2 gene looping defect, while SSU72 overexpression restored the formation of gene loops in rpb4Δ cells. Interestingly, the interaction of TFIIB with Ssu72 is compromised in rpb4Δ cells. These results suggest that the TFIIB–Ssu72 interaction, which is critical for gene loop formation, is facilitated by Rpb4. We propose that Rpb4 is promoting the transfer of RNAPII from the terminator to the promoter for reinitiation of transcription through TFIIB–Ssu72 mediated gene looping.

Vibrational Dephasing and Collision Induced Scattering in Molecular Liquids

1983 ◽  
Vol 22 ◽  
Author(s):  
Jiri Jonas
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Temperature Effects ◽  
Essential Role ◽  
Theoretical Models ◽  
Molecular Liquids ◽  
Vibrational Dephasing

ABSTRACTThe results of several Raman studies of vibrational dephasing in polyatomic molecular liquids at high pressure are reviewed. The density and temperature effects on vibrational dephasing of isotropic Raman bands for different vibrational models are reported for the following liquids: C(CH3)4; Si(CH3)4; Ge(CH3)4; ; Sn(CH3)4 and isobutylene CH2; = C(CH3) 2.The experimental data are used to test the current theoretical models of vibrational dephasing. Selected results of our high pressure experiments on collision induced scattering in polyatomic molecular liquids demonstrate well the essential role of high pressure in studying these phenomena.

The role of 5a-reduction in steroid hormone physiology

2001 ◽  
Vol 13 (8) ◽  
pp. 673 ◽  
Author(s):  
Jean D. Wilson
Keyword(s):  
Essential Role ◽  
Steroid Hormone ◽  
Urogenital Sinus ◽  
Receptor Complex ◽  
Hormone Action ◽  
Steroid Molecule ◽  
Male Development ◽  
Broad Specificity

A role for 5α-reduction in androgen physiology was first established with the recognition that dihydrotestosterone, the 5α-reduced metabolite of testosterone, is formed in many androgen target tissues, binds to the androgen receptor with greater affinity than testosterone, and plays an essential role in virilization of the urogenital sinus and urogenital tubercle during male development. Two 5α-reductases perform this reaction, and both isoenzymes utilize NADPH as cofactor and have broad specificity for steroids containing a Δ4, 3-keto configuration. 5α-Reduction, which is essentially irreversible, flattens the steroid molecule because of altered relation of the A and B rings, and stabilizes the hormone–receptor complex. Studies involving in vitro reporter gene assays and intact mice in which both isoenzymes are disrupted, indicate that the fundamental effect of dihydrotestosterone formation is to amplify hormonal signals that can be mediated by testosterone at higher concentrations. 5α-Reduction also plays a role in the action of other steroid hormones, including the plant growth hormone, brassinolide, the boar pheromones, androstanol and androstenol, progesterone (in some species), and, possibly, aldosterone and cortisol. The fact that the reaction is important in plants and animals implies a fundamental role in steroid hormone action.

scholarly journals The Roles of Sodium and Potassium Ions in the Generation of the Electro-Olfactogram

1968 ◽  
Vol 51 (4) ◽  
pp. 552-578 ◽  
Author(s):  
Sadayuki F. Takagi ◽  
Gordon A. Wyse ◽  
Harunobu Kitamura ◽  
Katsuhiro Ito
Keyword(s):  
Essential Role ◽  
Ringer Solution ◽  
The Other ◽  
Potassium Ions ◽  
Ionic Mechanism ◽  
Ringer’S Solution ◽  
Sodium And Potassium

In order to clarify whether or not the electronegative olfactory mucosal potentials (EOG) are generator potentials, the effects of changed ionic enviroment were studied. The EOG decreased in amplitude and in some cases nearly or completely disappeared, when Na+ in the bathing Ringer solution was replaced by sucrose, Li+, choline+, tetraethylammonium+ (TEA), or hydrazine. In the K+-free Ringer solution, the negative EOG's initially increased and then decreased in amplitude. In Ringer's solution with increased K+, the negative EOG's increased in amplitude. When K+ was increased in exchange for Na+ in Ringer's solution, the negative EOG's decreased, disappeared, and then reversed their polarity (Fig. 6). Next, when the K+ was replaced by equimolar sucrose, Li+, choline+, TEA+, hydrazine, or Na+, the reversed potentials recovered completely only in Na+-Ringer's solution, but never in the other solutions. Thus, the essential role of Na+ and K+ in the negative EOG's was demonstrated. Ba++ was found to depress selectively the electropositive EOG, but it hardly decreased and never increased the negative EOG. Hence, it is concluded that Ba++ interferes only with Cl- influx, and that the negative EOG's are elicited by an increase in permeability of the olfactory receptive membrane to Na+ and K+, but not to Cl-. From the ionic mechanism it is inferred that the negative EOG's are in most cases composites of generator and positive potentials.

scholarly journals DRIS Norms and Sufficiency Ranges for Pepper Grown under Greenhouses Conditions in the Southeast of Spain

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 837
Author(s):  
Alfonso Llanderal ◽  
Pedro García-Caparrós ◽  
María Teresa Lao ◽  
Maria Luz Segura
Keyword(s):  
Capsicum Annuum ◽  
Fruit Development ◽  
Essential Role ◽  
Integrated System ◽  
The Other ◽  
Phenological Stages ◽  
Capsicum Annuum L ◽  
Crop Nutrition

The aim of this study was to compile DRIS (Diagnosis and Recommendation Integrated System) norms and sufficiency ranges for pepper grown in greenhouses and the determination of the variation in DRIS norms and sufficiency ranges during the different phenological stages of the crop. The DRIS norms and sufficiency ranges were constituted by 367 leaf samples of Capsicum annuum L. which were collected in different phenological stages of the crop (flowering (FL), fruiting (FT), fruit development (FD), and harvesting (HV)). Two sufficiency ranges were developed; one including all leaf samples and the other considering the leaf samples by phenological stages ((FL) (44), (FT) (96), (FD) (100), and (HV) (127)). Furthermore, 10 DRIS norms and CV were calculated from N, P, K, Ca, and Mg. Two ratios of them were calculated in FL (N/P and N/K), two in FD (N/P and Ca/N) and one in HV (N/P) showing low CV, meaning, according to DRIS norms, the essential role of these nutrients in the crop nutrition. Moreover, the sufficiency ranges computed by all database were: N (34–56), P (1.9–4.3), K (30–51), Ca (12–33), and Mg (4.0–15) (mg g−1 DW), respectively. The data obtained in this experiment highlighted the importance of the sensitivity (low CV) of nutrient in the phenological stages such as happened with N.

scholarly journals Lockdown e “Chiesa in uscita”. Un caso di studio in Italia: la fraternità “AGBP”

2021 ◽  
Vol 6 (13) ◽  
pp. 131-142
Author(s):  
Daniela Turco
Keyword(s):  
Catholic Church ◽  
Essential Role ◽  
Social Bonds ◽  
The Other ◽  
Focus Attention ◽  
Daily Lives ◽  
On Line ◽  
The Many ◽  
The One

The impetuosity of the Sars-Covid 2 infection has been remarkable, quickly upsetting the habits of individuals in every seat of the planet. We can observe, on the one hand, the individuals, lost and called to redefine every area of their daily lives. On the other, the institutions that, seizing this loss, have been called to play their essential role of creating and strengthening social bonds. The Catholic Church has promoted respect for the norms, without renouncing a “religious offer” which seems to have responded to an effective demand for accompaniment with a lot of possibility to chose on line liturgical celebrations, with a multiplicity of forms and possibilities of access. Among the various options possible, it was decided to focus attention on a specific case: the case of the fraternity “Amici di Gesù Buon Pastore” (AGBP), which has experienced a significant increase in its followers in the days of lockdown. In particular, we will ask ourselves what so many spiritual-followers have been looking for and if (and how) this interest, born during the quarantine period, can transform the new forms of religious belonging into a context where the historical religions seem to be unattractive if compared to the many alternatives of spirituality present on the “market”.

scholarly journals On the role of the H-2 histocompatibility complex in determining the specificity of cytotoxic effector cells sensitized against syngeneic trinitrophenyl-modified targets.

1975 ◽  
Vol 142 (2) ◽  
pp. 403-418 ◽  
Author(s):  
J Forman
Keyword(s):  
Target Cell ◽  
Parental Strain ◽  
Cytotoxic Effect ◽  
Effector Cell ◽  
The Other ◽  
Spleen Cells ◽  
F1 Hybrid ◽  
Effector Cells ◽  
D Region

Spleen cells cultured with syngeneic trinitrophenyl (TNP)-modified stimulator cells display a cytotoxic effect against syngeneic TNP-modified targets, but not against modified targets from unrelated H-2 haplotypes. Targets that share the K and I region of the H-2 complex with the stimulator (or effector) cell are lysed to the same extent as the specific targets, while targets that share the I region only are not. When only the D region is shared, a weak cytotoxic effect is observed. Therefore, the stimulator (or effector) and target cell must share the K or D but not the I region of the H-2 complex in order for optimal cytotoxicity to occur. Spleen cells sensitized to irradiated TNP-modified H-2-allogeneic cells are cytotoxic to these specific cells. Coculture of F1 hybrid cells with irradiated TNP-modified parental cells result in a cytotoxic effect against only those specific parental cells and not TNP-modified cells from the other parent. The cytotoxic effect of the F1 effector cells in the cell-mediated lympholysis test is blocked by the addition of unlabeled TNP-modified targets that are H-2 syngeneic with the sensitizing parental strain, but not H-2 syngeneic with the other parental strain. These data demonstrate that the specificity of the effector cell in this syngeneic cytotoxicity system is directed against altered self H-2-controlled-gene products, rather than a requirement for sharing of histocompatibility genes between effector and target cell in order for lysis to occur. The role of H-2 antigens in determining the sensitivity of a target cell to T-cell-mediated lysis is discussed.

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