The role of trehalose-6-phosphate synthase in Arabidopsis embryo development

2005 ◽  
Vol 33 (1) ◽  
pp. 280-282 ◽  
Author(s):  
L.D. Gómez ◽  
S. Baud ◽  
I.A. Graham
Keyword(s):  
Embryo Development ◽  
Wild Type ◽  
Cotyledon Stage ◽  
Expression Of Genes ◽  
Developmental Progression ◽  
Storage Reserve ◽  
Trehalose Synthesis ◽  
Storage Reserves ◽  
Phosphate Synthase

We previously showed that trehalose-6-phosphate synthase 1 (TPS1), which catalyses the first step in trehalose synthesis, is essential for embryo maturation in Arabidopsis [Eastmond, van Dijken, Spielman, Kerr, Tissier, Dickinson, Jones, Smeekens and Graham (2002) Plant J. 29, 225–235]. The tps1 mutant embryos develop more slowly than wild type. Patterning in the tps1 embryos appears normal but they do not progress past the torpedo stage to cotyledon stage, which is when storage reserves start to accumulate in the expanding cotyledons. Our initial data led to the hypothesis that trehalose metabolism plays a key role in regulating storage reserve accumulation by allowing the embryo to respond to the dramatic increase in sucrose levels that occurs at the torpedo stage of embryo development. More recent data demonstrate that while the tps1 mutant is blocked in the developmental progression of embryos from torpedo to cotyledon stage the expression of genes involved in the accumulation of storage reserves proceeds in a similar fashion to wild type. Thus it appears that induction of metabolic processes required for accumulation of storage reserves in tps1 occurs independently of the developmental stage and instead follows a temporal programme similar to wild-type seeds in the same silique.

scholarly journals Loss of resistin ameliorates hyperlipidemia and hepatic steatosis in leptin-deficient mice

2008 ◽  
Vol 295 (2) ◽  
pp. E331-E338 ◽  
Author(s):  
Neel S. Singhal ◽  
Rajesh T. Patel ◽  
Yong Qi ◽  
Yun-Sik Lee ◽  
Rexford S. Ahima
Keyword(s):  
Hepatic Steatosis ◽  
High Fat Diet ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Wild Type ◽  
The Metabolic Syndrome ◽  
Expression Of Genes ◽  
Similar Body ◽  
Deficient Mice

Resistin has been linked to components of the metabolic syndrome, including obesity, insulin resistance, and hyperlipidemia. We hypothesized that resistin deficiency would reverse hyperlipidemia in genetic obesity. C57Bl/6J mice lacking resistin [resistin knockout (RKO)] had similar body weight and fat as wild-type mice when fed standard rodent chow or a high-fat diet. Nonetheless, hepatic steatosis, serum cholesterol, and very low-density lipoprotein (VLDL) secretion were decreased in diet-induced obese RKO mice. Resistin deficiency exacerbated obesity in ob/ob mice, but hepatic steatosis was drastically attenuated. Moreover, the levels of triglycerides, cholesterol, insulin, and glucose were reduced in ob/ob-RKO mice. The antisteatotic effect of resistin deficiency was related to reductions in the expression of genes involved in hepatic lipogenesis and VLDL export. Together, these results demonstrate a crucial role of resistin in promoting hepatic steatosis and hyperlipidemia in obese mice.

scholarly journals The PAF1 complex cell-autonomously promotes oogenesis in Caenorhabditis elegans

2021 ◽  
Author(s):  
Yukihiko Kubota ◽  
Natsumi Ota ◽  
Hisashi Takatsuka ◽  
Takuma Unno ◽  
Shuichi Onami ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Rna Polymerase Ii ◽  
Oocyte Maturation ◽  
Germ Line ◽  
Biological Processes ◽  
Wild Type ◽  
Expression Of Genes ◽  
A Cell ◽  
Precise Role

The RNA polymerase II-associated factor 1 complex (PAF1C) is a protein complex that consists of LEO1, RTF1, PAF1, CDC73, and CTR9, and has been shown to be involved in Pol II-mediated transcriptional and chromatin regulation. Although it has been shown to regulate a variety of biological processes, the precise role of the PAF1C during germ line development has not been clarified. In this study, we found that reduction in the function of the PAF1C components, LEO-1, RTFO-1, PAFO-1, CDC-73, and CTR-9, in Caenorhabditis elegans affects cell volume expansion of oocytes. Defects in oogenesis were also confirmed using an oocyte maturation marker, OMA-1::GFP. While four to five OMA-1::GFP-positive oocytes were observed in wild-type animals, their numbers were significantly decreased in pafo-1 mutantand leo-1(RNAi), cdc-73(RNAi), and pafo-1(RNAi) animals. Expression of a functional PAFO-1::mCherry transgene in the germline significantly rescued the oogenesis-defective phenotype of the pafo-1 mutants, suggesting that expression of the PAF1C in germ cells is required for oogenesis. Notably, overexpression of OMA-1::GFP partially rescued the oogenesis defect in the pafo-1 mutants. Based on our findings, we propose that the PAF1C promotes oogenesis in a cell-autonomous manner by positively regulating the expression of genes involved in oocyte maturation.

scholarly journals WhiB5, a Transcriptional Regulator That Contributes to Mycobacterium tuberculosis Virulence and Reactivation

2012 ◽  
Vol 80 (9) ◽  
pp. 3132-3144 ◽  
Author(s):  
Stefano Casonato ◽  
Axel Cervantes Sánchez ◽  
Hirohito Haruki ◽  
Monica Rengifo González ◽  
Roberta Provvedi ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Chronic Infection ◽  
Null Mutant ◽  
Wild Type ◽  
Secretion Systems ◽  
Content Type ◽  
Type Vii Secretion ◽  
Expression Of Genes ◽  
Genes Encoding

ABSTRACTThe proteins belonging to the WhiB superfamily are small global transcriptional regulators typical of actinomycetes. In this paper, we characterize the role of WhiB5, aMycobacterium tuberculosisprotein belonging to this superfamily. A null mutant was constructed inM. tuberculosisH37Rv and was shown to be attenuated during both progressive and chronic mouse infections. Mice infected with the mutant had smaller bacillary burdens in the lungs but a larger inflammatory response, suggesting a role of WhiB5 in immunomodulation. Most interestingly, thewhiB5mutant was not able to resume growth after reactivation from chronic infection, suggesting that WhiB5 controls the expression of genes involved in this process. The mutant was also more sensitive than the wild-type parental strain toS-nitrosoglutathione (GSNO) and was less metabolically active following prolonged starvation, underscoring the importance of GSNO and starvation in development and maintenance of chronic infection. DNA microarray analysis identified 58 genes whose expression is influenced by WhiB5, includingsigM, encoding an alternative sigma factor, and genes encoding the constituents of two type VII secretion systems, namely, ESX-2 and ESX-4.

scholarly journals Role of RpoS in the Virulence of Citrobacter rodentium

2008 ◽  
Vol 77 (1) ◽  
pp. 501-507 ◽  
Author(s):  
Tao Dong ◽  
Brian K. Coombes ◽  
Herb E. Schellhorn
Keyword(s):  
Pathogenicity Island ◽  
Competitive Growth ◽  
Citrobacter Rodentium ◽  
Wild Type ◽  
E Coli ◽  
Mouse Colon ◽  
Expression Of Genes

ABSTRACT Citrobacter rodentium is a mouse enteropathogen that is closely related to Escherichia coli and causes severe colonic hyperplasia and bloody diarrhea. C. rodentium infection requires expression of genes of the locus of enterocyte effacement (LEE) pathogenicity island, which simulates infection by enteropathogenic E. coli and enterohemorrhagic E. coli in the human intestine, providing an effective model for studying enteropathogenesis. In this study we investigated the role of RpoS, the stationary phase sigma factor, in virulence in C. rodentium. Sequence analysis showed that the rpoS gene is highly conserved in C. rodentium and E. coli, exhibiting 92% identity. RpoS was critical for survival under heat shock conditions and during exposure to H2O2 and positively regulated the expression of catalase KatE (HPII). The development of the RDAR (red dry and rough) morphotype, an important virulence trait in E. coli, was also mediated by RpoS in C. rodentium. Unlike E. coli, C. rodentium grew well in the mouse colon, and the wild-type strain colonized significantly better than rpoS mutants. However, a mutation in rpoS conferred a competitive growth advantage over the wild type both in vitro in Luria-Bertani medium and in vivo in the mouse colon. Survival analysis showed that the virulence of an rpoS mutant was attenuated. The expression of genes on the LEE pathogenicity island, which are essential for colonization and virulence, was reduced in the rpoS mutant. In conclusion, RpoS is important for the stress response and is required for full virulence in C. rodentium.

scholarly journals Transcriptomics-Aided Dissection of the Intracellular and Extracellular Roles of Microcystin in Microcystis aeruginosa PCC 7806

2014 ◽  
Vol 81 (2) ◽  
pp. 544-554 ◽  
Author(s):  
A. Katharina Makower ◽  
J. Merijn Schuurmans ◽  
Detlef Groth ◽  
Yvonne Zilliges ◽  
Hans C. P. Matthijs ◽  
...  
Keyword(s):  
Polyketide Synthase ◽  
Wild Type Strain ◽  
Carbon Limitation ◽  
Light Conditions ◽  
Wild Type ◽  
Low Light ◽  
Content Type ◽  
Expression Of Genes ◽  
Polyketide Synthase Gene

ABSTRACTRecent studies have provided evidence for both intracellular and extracellular roles of the potent hepatotoxin microcystin (MC) in the bloom-forming cyanobacteriumMicrocystis. Here, we surveyed transcriptomes of the wild-type strainM. aeruginosaPCC 7806 and the microcystin-deficient ΔmcyBmutant under low light conditions with and without the addition of external MC of the LR variant (MC-LR). Transcriptomic data acquired by microarray and quantitative PCR revealed substantial differences in the relative expression of genes of the central intermediary metabolism, photosynthesis, and energy metabolism. In particular, the data provide evidence for a lower photosystem I (PSI)-to-photosystem II (PSII) ratio and a more pronounced carbon limitation in the microcystin-deficient mutant. Interestingly, only 6% of the transcriptional differences could be complemented by external microcystin-LR addition. This MC signaling effect was seen exclusively for genes of the secondary metabolism category. The orphan polyketide synthase gene cluster IPF38-51 was specifically downregulated in response to external MC-LR under low light. Our data suggest a hierarchical and light-dependent cross talk of secondary metabolites and support both an intracellular and an extracellular role of MC inMicrocystis.

scholarly journals Involvement of H-NS in Acinetobacter baumannii’s Natural Transformation

2021 ◽  
Author(s):  
Casin Le ◽  
Camila Pimentel ◽  
Marisel Romina Tuttobene ◽  
Tomás Subils ◽  
Jenny Escalante ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Wild Type Strain ◽  
Natural Transformation ◽  
Regulatory Elements ◽  
Wild Type ◽  
Regulation Of Expression ◽  
Expression Levels ◽  
Expression Of Genes ◽  
Foreign Dna

Most Acinetobacter baumannii strains are naturally competent. Although some information is available about factors that enhance or reduce the frequency of transformation of this bacterium, the regulatory elements and mechanisms are barely understood. In this article, we describe studies on the role of H-NS in the regulation of expression of genes related to natural competency and the ability to uptake foreign DNA. The expression levels of the natural transformation-related genes pilA, pilT, pilQ, comEA, comEC, comF, and drpA were significantly increased in a Δhns derivative of Acinetobacter baumannii A118. Complementation of the mutant with a recombinant plasmid harboring hns restored expression levels of six of these genes (pilT remained expressed at high levels) to those of the wild-type strain. The transformation frequency of the A. baumannii A118 Δhns strain was significantly higher than that of the wild-type. Similar, albeit not identical, effects occurred when hns was deleted from the hypervirulent A. baumannii AB5075 strain. Reduction of gene expression in a few cases was not as pronounced as to reach wild-type levels, and expression of comEA was enhanced further. In conclusion, the expression of all seven transformation-related genes was enhanced after deleting hns in A. baumannii A118 and AB5075, and these modifications are accompanied by an increase in the cells’ transformability. The results demonstrate a role of H-NS in A. baumannii’s natural competence.

scholarly journals Intestinal Farnesoid X Receptor Signaling Modulates Metabolic Disease

2017 ◽  
Vol 35 (3) ◽  
pp. 178-184 ◽  
Author(s):  
Frank J. Gonzalez ◽  
Changtao Jiang ◽  
Cen Xie ◽  
Andrew D. Patterson
Keyword(s):  
Metabolic Disease ◽  
Small Intestine ◽  
Metabolic Diseases ◽  
Enterohepatic Circulation ◽  
Farnesoid X Receptor ◽  
Wild Type ◽  
Expression Of Genes ◽  
Ceramide Synthesis ◽  
Agonist And Antagonist

Farnesoid X receptor (FXR) regulates the synthesis, transport and enterohepatic circulation of bile acids (BA) by modulating the expression of related genes in the liver and small intestine. The composition of the gut microbiota is correlated with metabolic diseases, notably obesity and non-alcoholic fatty acid disease (NAFLD). Recent studies revealed that bacterial metabolism of BA can modulate FXR signaling in the intestine by altering the composition and concentrations of FXR agonist and antagonist. FXR agonist enhances while FXR antagonist suppresses obesity, NAFLD and insulin resistance. The role of intestinal FXR in metabolic disease was firmly established by the analysis of mice lacking FXR that are metabolic resistant to HFD-induced metabolic disease. This is mediated by FXR modulating in part the expression of genes involved in ceramide synthesis in the small intestine. In ileum of obese mice due to the presence of endogenous FXR agonists produced in the liver, these genes are activated, while in mice with altered levels of specific gut bacteria, levels of an FXR antagonist, tauro-β-muricholic acid (T-β-MCA) increase and FXR signaling and ceramide synthesis are repressed. T-β-MCA, which is metabolized in wild-type mice, led to the discovery of glycine-β-muricholic acid (Gly-MCA) that is stable in the intestine and a potent inhibitor of FXR signaling. These studies reveal that ceramides produced in the ileum under the control of FXR, influence metabolic disease, and suggest that novel FXR antagonist such as Gly-MCA that specifically inhibit intestine FXR, could serve as potential drug for the treatment of metabolic disease.

scholarly journals Tomato Prosystemin is much more than a simple Systemin precursor

2021 ◽  
Author(s):  
Donata Molisso ◽  
Mariangela Coppola ◽  
Martina Buonanno ◽  
Ilaria Di Lelio ◽  
Simona Maria Monti ◽  
...  
Keyword(s):  
Plant Immunity ◽  
Defense Responses ◽  
Wild Type ◽  
Carboxy Terminus ◽  
Tomato Plants ◽  
Expression Of Genes ◽  
Transgenic Tomato Plants ◽  
Lepidopteran Pest ◽  
Dependent Pathway

SummarySystemin (Sys) is an octadecapeptide which, upon wounding, is released from the carboxy terminus of its precursor, prosystemin(ProSys) to promote plant defenses. Recent findings on the disordered structure of ProSysprompted us to investigate a putative biological role of the whole precursor deprived of Sys peptide. We produced transgenic tomato plants expressing a truncated ProSys gene in which the exon coding for Sys was removed and compared their defense response with that induced by the exogenous application of the recombinant deleted ProSys[ProSys(1-178)].By combining protein structure analyses, transcriptomic analysis, gene expression profiling and bioassays with different pests we demonstrate that the truncated ProSys, that does not induce the endogenous ProSys gene, promotes defense barriers in tomato plants through a hormone independent defense pathway, likely associated with the production of oligogalacturonides (OGs). Both transgenic and plants treated with the recombinant protein showed the modulation of the expression of genes linked with defense responses and resulted protected against the lepidopteran pest Spodoptera littoralis and the fungus Botrytis cinerea. Our results suggest that the overall function of the wild type prosystemin is more complex than previously shown as it might activate at least two tomato defense pathways: the well-known Sys-dependent pathway connected with the induction of JA biosynthesis and the successive activation of a set of defense-related genes and the ProSys(1-178)-dependent pathway associated with OGs production leading to the OGs mediate plant immunity.

scholarly journals ROLE OF SEED STORAGE RESERVES IN OSMOCONDITIONING OF SWEET CORN

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 662a-662
Author(s):  
G.B. McClure ◽  
N.S. Lang
Keyword(s):  
Sweet Corn ◽  
Seed Storage ◽  
Germination Percentage ◽  
Distilled Water ◽  
Water Potentials ◽  
Seed Moisture ◽  
Storage Reserve ◽  
Seed Storage Reserves ◽  
Storage Reserves

Interconversions of seed storage reserves during osmoconditioning (controlled imbibition of water) may influence seed performance under suboptimal conditions. Sweet corn (Zen mays L. cv. Florida Staysweet) storage reserve changes were examined during osmoconditioning in relation to seed germination performance. Seeds were osmoconditioned in two experiments using distilled water (duration 3, 6, 9, 12, and 24 h) and polyethylene glycol 8000 solutions (0, .5, and 1.0 MPa for 12, 24, 48, 72 and 96 h). Germination performance was evaluated at 10 and 25C, and seed moisture, carbohydrate, and protein concentrations were quantified at each water potential x duration combination. Germination performance was not significantly improved by any treatment at 25C. Germination percentage at 10C was increased 10% for seeds osmoconditioned for 24 h in distilled water, and time to germination was decreased 50%. For seeds osmoconditioned 12 and 48 h at .5 and 1.0 MPa, respectively, germination percentage at 10C was increased 15%. Time to germination was reduced 50% for seeds osmoconditioned at .5 and 1.0 MPa after 48 and 96 h, respectively. Starch levels increased for seeds osmoconditioned at higher water potentials, but remained the same or decreased at lower water potentials.

scholarly journals Dissecting the functions of NIPBL using genome editing: The importance of the N-terminus of NIPBL in transcriptional regulation

2019 ◽  
Author(s):  
Kosuke Izumi ◽  
Kazuhiro Akiyama ◽  
Katsunori Fujiki ◽  
Koji Masuda ◽  
Ryuichiro Nakato ◽  
...  
Keyword(s):  
Fine Tuning ◽  
Regulatory Subunit ◽  
Wild Type ◽  
Transcriptional Dysregulation ◽  
Expression Of Genes ◽  
Transcriptional Regulatory ◽  
N Terminus ◽  
Cornelia De Lange ◽  
Gene Expression Levels

ABSTRACTCornelia de Lange syndrome (CdLS) is characterized by craniofacial dysmorphisms, intellectual disabilities, growth retardation, and several other systemic abnormalities. CdLS is caused by heterozygous germline mutations in structural and regulatory components of cohesin. Mutations in NIPBL, which encodes regulatory subunit of cohesin, are frequently found in individuals with CdLS. CdLS is associated with a currently unknown mechanism of global transcriptional dysregulation. In this study, NIPBL mutants were generated using the CRISPR/Cas9 system to study this mechanism. Clones with a biallelic frameshift mutation in exon 3 of NIPBL, resulting in a truncated N-terminus, displayed transcriptional dysregulation without sister chromatid separation defects. Detailed transcriptome analysis revealed the overexpression of genes in NIPBL mutants that are typically expressed at low levels in wild type and the reduced expression of genes that are typically expressed at high levels in wild type. This result suggested that NIPBL plays a role in fine-tuning gene expression levels. MAU2 protein, that closely interacts with NIPBL, was nearly absent in these clones. The reduction of MAU2 observed in NIPBL mutants points to the importance of the NIPBL N-terminus/MAU2 interaction in transcriptional regulatory role of NIPBL.

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