scholarly journals GhVTC1, the Key Gene for Ascorbate Biosynthesis in Gossypium hirsutum, Involves in Cell Elongation Under Control of Ethylene

Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1039 ◽  
Author(s):  
Song ◽  
Wang ◽  
Chen ◽  
Ma ◽  
Zuo ◽  
...  
Keyword(s):  
Cell Growth ◽  
Gossypium Hirsutum ◽  
Cell Elongation ◽  
Regulatory Mechanism ◽  
De Novo ◽  
Primary Root ◽  
Ectopic Expression ◽  
Cellular Level ◽  
Loss Of Function ◽  
Ethylene Signaling Pathway

L-Ascorbate (Asc) plays important roles in cell growth and plant development, and its de novo biosynthesis was catalyzed by the first rate-limiting enzyme VTC1. However, the function and regulatory mechanism of VTC1 involved in cell development is obscure in Gossypium hirsutum. Herein, the Asc content and AsA/DHA ratio were accumulated and closely linked with fiber development. The GhVTC1 encoded a typical VTC1 protein with functional conserved domains and expressed preferentially during fiber fast elongation stages. Functional complementary analysis of GhVTC1 in the loss-of-function Arabidopsis vtc1-1 mutants indicated that GhVTC1 is genetically functional to rescue the defects of mutants to normal or wild type (WT). The significant shortened primary root in vtc1-1 mutants was promoted to the regular length of WT by the ectopic expression of GhVTC1 in the mutants. Additionally, GhVTC1 expression was induced by ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), and the GhVTC1 promoter showed high activity and included two ethylene-responsive elements (ERE). Moreover, the 5’-truncted promoters containing the ERE exhibited increased activity by ACC treatment. Our results firstly report the cotton GhVTC1 function in promoting cell elongation at the cellular level, and serve as a foundation for further understanding the regulatory mechanism of Asc-mediated cell growth via the ethylene signaling pathway.

scholarly journals A Cotton (Gossypium hirsutum) Myo-Inositol-1-Phosphate Synthase (GhMIPS1D) Gene Promotes Root Cell Elongation in Arabidopsis

2019 ◽  
Vol 20 (5) ◽  
pp. 1224 ◽  
Author(s):  
Rendi Ma ◽  
Wangyang Song ◽  
Fei Wang ◽  
Aiping Cao ◽  
Shuangquan Xie ◽  
...  
Keyword(s):  
Cell Growth ◽  
Gossypium Hirsutum ◽  
Cell Elongation ◽  
Evolutionary Dynamics ◽  
Primary Root ◽  
Ectopic Expression ◽  
Fiber Cell ◽  
Root Cells ◽  
Inositol 1 ◽  
Phosphate Synthase

Myo-inositol-1-phosphate synthase (MIPS, EC 5.5.1.4) plays important roles in plant growth and development, stress responses, and cellular signal transduction. MIPS genes were found preferably expressed during fiber cell initiation and early fast elongation in upland cotton (Gossypium hirsutum), however, current understanding of the function and regulatory mechanism of MIPS genes to involve in cotton fiber cell growth is limited. Here, by genome-wide analysis, we identified four GhMIPS genes anchoring onto four chromosomes in G. hirsutum and analyzed their phylogenetic relationship, evolutionary dynamics, gene structure and motif distribution, which indicates that MIPS genes are highly conserved from prokaryotes to green plants, with further exon-intron structure analysis showing more diverse in Brassicales plants. Of the four GhMIPS members, based on the significant accumulated expression of GhMIPS1D at the early stage of fiber fast elongating development, thereby, the GhMIPS1D was selected to investigate the function of participating in plant development and cell growth, with ectopic expression in the loss-of-function Arabidopsis mips1 mutants. The results showed that GhMIPS1D is a functional gene to fully compensate the abnormal phenotypes of the deformed cotyledon, dwarfed plants, increased inflorescence branches, and reduced primary root lengths in Arabidopsis mips1 mutants. Furthermore, shortened root cells were recovered and normal root cells were significantly promoted by ectopic expression of GhMIPS1D in Arabidopsis mips1 mutant and wild-type plants respectively. These results serve as a foundation for understanding the MIPS family genes in cotton, and suggest that GhMIPS1D may function as a positive regulator for plant cell elongation.

scholarly journals Epstein–Barr virus-encoded latent membrane protein 1 and B-cell growth transformation induces lipogenesis through fatty acid synthase.

2020 ◽  
Author(s):  
Michael Hulse ◽  
Sarah M Johnson ◽  
Sarah Boyle ◽  
Lisa Beatrice Caruso ◽  
Italo Tempera
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
B Cells ◽  
Cell Growth ◽  
B Cell ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Ectopic Expression ◽  
Barr Virus ◽  
Growth Transformation

Latent membrane protein 1 (LMP1) is the major transforming protein of Epstein-Barr virus (EBV) and is critical for EBV-induced B-cell transformation in vitro. Several B-cell malignancies are associated with latent LMP1-positive EBV infection, including Hodgkin’s and diffuse large B-cell lymphomas. We have previously reported that promotion of B cell proliferation by LMP1 coincided with an induction of aerobic glycolysis. To further examine LMP1-induced metabolic reprogramming in B cells, we ectopically expressed LMP1 in an EBV-negative Burkitt’s lymphoma (BL) cell line preceding a targeted metabolic analysis. This analysis revealed that the most significant LMP1-induced metabolic changes were to fatty acids. Significant changes to fatty acid levels were also found in primary B cells following EBV-mediated B-cell growth transformation. Ectopic expression of LMP1 and EBV-mediated B-cell growth transformation induced fatty acid synthase (FASN) and increased lipid droplet formation. FASN is a crucial lipogenic enzyme responsible for de novo biogenesis of fatty acids in transformed cells. Furthermore, inhibition of lipogenesis caused preferential killing of LMP1-expressing B cells and significantly hindered EBV immortalization of primary B-cells. Finally, our investigation also found that USP2a, a ubiquitin-specific protease, is significantly increased in LMP1-positive BL cells and mediates FASN stability. Our findings demonstrate that ectopic expression of LMP1 and EBV-mediated B-cell growth transformation leads to induction of FASN, fatty acids and lipid droplet formation, possibly pointing to a reliance on lipogenesis. Therefore, the use of lipogenesis inhibitors could potentially be used in the treatment of LMP1+ EBV associated malignancies by targeting a LMP1-specific dependency on lipogenesis. Importance Despite many attempts to develop novel therapies, EBV-specific therapies currently remain largely investigational and EBV-associated malignancies are often associated with a worse prognosis. Therefore, there is a clear demand for EBV-specific therapies for both prevention and treatment of viral-associated malignancies. Non-cancerous cells preferentially obtain fatty acids from dietary sources whereas cancer cells will often produce fatty acids themselves by de novo lipogenesis, often becoming dependent on the pathway for cell survival and proliferation. LMP1 and EBV-mediated B-cell growth transformation leads to induction of FASN, a key enzyme responsible for the catalysis of endogenous fatty acids. Preferential killing of LMP1-expressing B cells following inhibition of FASN suggests that targeting LMP-induced lipogenesis could be an effective strategy in treating LMP1-positive EBV-associated malignancies. Importantly, targeting unique metabolic perturbations induced by EBV could be a way to explicitly target EBV-positive malignancies and distinguish their treatment from EBV-negative counterparts.

scholarly journals Golgi-localized TMN1/EMP12 functions in the deposition of rhamnogalacturonan II and I for cell growth in Arabidopsis

2021 ◽  
Author(s):  
Akihiko Hiroguchi ◽  
Shingo Sakamoto ◽  
Nobutaka Mitsuda ◽  
Kyoko Miwa
Keyword(s):  
Cell Growth ◽  
Cell Walls ◽  
Stem Elongation ◽  
Primary Root ◽  
Loss Of Function ◽  
Wild Type ◽  
Pectic Polysaccharides ◽  
Rhamnogalacturonan I ◽  
Rhamnogalacturonan Ii ◽  
Dependent Growth

Abstract Appropriate pectin deposition in cell walls is important for cell growth in plants. Rhamnogalacturonan II (RG-II) is a portion of pectic polysaccharides; its borate crosslinking is essential for maintenance of pectic networks. However, the overall process of RG-II synthesis is not fully understood. To identify a novel factor for RG-II deposition or dimerization in cell walls, we screened Arabidopsis mutants with altered boron (B)-dependent growth. The mutants exhibited alleviated disorders of primary root (PR) and stem elongation, and fertility under low B conditions, but reduced PR lengths under sufficient B conditions. Altered PR elongation was associated with cell elongation changes caused by loss of function in TMN1 (Transmembrane Nine 1) /EMP12, which encodes a Golgi-localized membrane protein of unknown function that is conserved among eukaryotes. Mutant leaf and root dry weights were lower than those of wild-type plants, regardless of B conditions. In cell walls, TMN1 mutations reduced contents of B, RG-II specific 2-keto-3-deoxy monosaccharides, and rhamnose largely derived from rhamnogalacturonan I (RG-I), suggesting reduced RG-II and RG-I. Together, our findings demonstrate that TMN1 is required for the deposition of RG-II and RG-I for cell growth and we also find that pectin levels modulate plant growth under low B conditions.

scholarly journals The Role of Protein Arginine Methylation as Post-Translational Modification on Actin Cytoskeletal Components in Neuronal Structure and Function

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1079
Author(s):  
Britta Qualmann ◽  
Michael M. Kessels
Keyword(s):  
Actin Filament ◽  
Regulatory Mechanism ◽  
De Novo ◽  
Arginine Methylation ◽  
Loss Of Function ◽  
Filament Formation ◽  
Post Translational Modification ◽  
Neuronal Structure ◽  
Actin Nucleation ◽  
Protein Arginine Methylation

The brain encompasses a complex network of neurons with exceptionally elaborated morphologies of their axonal (signal-sending) and dendritic (signal-receiving) parts. De novo actin filament formation is one of the major driving and steering forces for the development and plasticity of the neuronal arbor. Actin filament assembly and dynamics thus require tight temporal and spatial control. Such control is particularly effective at the level of regulating actin nucleation-promoting factors, as these are key components for filament formation. Arginine methylation represents an important post-translational regulatory mechanism that had previously been mainly associated with controlling nuclear processes. We will review and discuss emerging evidence from inhibitor studies and loss-of-function models for protein arginine methyltransferases (PRMTs), both in cells and whole organisms, that unveil that protein arginine methylation mediated by PRMTs represents an important regulatory mechanism in neuritic arbor formation, as well as in dendritic spine induction, maturation and plasticity. Recent results furthermore demonstrated that arginine methylation regulates actin cytosolic cytoskeletal components not only as indirect targets through additional signaling cascades, but can also directly control an actin nucleation-promoting factor shaping neuronal cells—a key process for the formation of neuronal networks in vertebrate brains.

scholarly journals miR156-targeted SPL10 controls Arabidopsis root meristem activity and root-derived de novo shoot regeneration via cytokinin responses

2019 ◽  
Vol 71 (3) ◽  
pp. 934-950 ◽  
Author(s):  
Carlos Hernán Barrera-Rojas ◽  
Gabriel Henrique Braga Rocha ◽  
Laura Polverari ◽  
Diego Armando Pinheiro Brito ◽  
Diego Silva Batista ◽  
...  
Keyword(s):  
Shoot Regeneration ◽  
Root Meristem ◽  
De Novo ◽  
Expression Patterns ◽  
Primary Root ◽  
Loss Of Function ◽  
Arabidopsis Root ◽  
Squamosa Promoter Binding Protein ◽  
Spl Genes ◽  
Dependent Pathway

Abstract Root growth is modulated by different factors, including phytohormones, transcription factors, and microRNAs (miRNAs). MicroRNA156 and its targets, the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) genes, define an age-dependent pathway that controls several developmental processes, including lateral root emergence. However, it remains unclear whether miR156-regulated SPLs control root meristem activity and root-derived de novo shoot regeneration. Here, we show that MIR156 and SPL genes have opposing expression patterns during the progression of primary root (PR) growth in Arabidopsis, suggesting that age cues may modulate root development. Plants with high miR156 levels display reduced meristem size, resulting in shorter primary root (PRs). Conversely, plants with reduced miR156 levels show higher meristem activity. Importantly, loss of function of SPL10 decreases meristem activity, while SPL10 de-repression increases it. Meristem activity is regulated by SPL10 probably through the reduction of cytokinin responses, via the modulation of type-B ARABIDOPSIS RESPONSE REGULATOR1(ARR1) expression. We also show that SPL10 de-repression in the PRs abolishes de novo shoot regenerative capacity by attenuating cytokinin responses. Our results reveal a cooperative regulation of root meristem activity and root-derived de novo shoot regeneration by integrating age cues with cytokinin responses via miR156-targeted SPL10.

scholarly journals Epstein–Barr virus-encoded latent membrane protein 1 and B-cell growth transformation induces lipogenesis through fatty acid synthase

2019 ◽  
Author(s):  
Michael Hulse ◽  
Sarah M Johnson ◽  
Sarah Boyle ◽  
Lisa Beatrice Caruso ◽  
Italo Tempera
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
B Cells ◽  
Cell Growth ◽  
B Cell ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Ectopic Expression ◽  
Barr Virus ◽  
Growth Transformation

AbstractLatent membrane protein 1 (LMP1) is the major transforming protein of Epstein-Barr virus (EBV) and is critical for EBV-induced B-cell transformation in vitro. Several B-cell malignancies are associated with latent LMP1-positive EBV infection, including Hodgkin’s and diffuse large B-cell lymphomas. We have previously reported that promotion of B cell proliferation by LMP1 coincided with an induction of aerobic glycolysis. To further examine LMP1-induced metabolic reprogramming in B cells, we ectopically expressed LMP1 in an EBV-negative Burkitt’s lymphoma (BL) cell line preceding a targeted metabolic analysis. This analysis revealed that the most significant LMP1-induced metabolic changes were to fatty acids. Significant changes to fatty acid levels were also found in primary B cells following EBV-mediated B-cell growth transformation.Ectopic expression of LMP1 and EBV-mediated B-cell growth transformation induced fatty acid synthase (FASN) and increased lipid droplet formation. FASN is a crucial lipogenic enzyme responsible for de novo biogenesis of fatty acids in transformed cells. Furthermore, inhibition of lipogenesis caused preferential killing of LMP1-expressing B cells and significantly hindered EBV immortalization of primary B-cells. Finally, our investigation also found that USP2a, a ubiquitin-specific protease, is significantly increased in LMP1-positive BL cells and mediates FASN stability. Our findings demonstrate that ectopic expression of LMP1 and EBV-mediated B-cell growth transformation leads to induction of FASN, fatty acids and lipid droplet formation, possibly pointing to a reliance on lipogenesis. Therefore, the use of lipogenesis inhibitors could potentially be used in the treatment of LMP1+ EBV associated malignancies by targeting a LMP1-specific dependency on lipogenesis.ImportanceDespite many attempts to develop novel therapies, EBV-specific therapies currently remain largely investigational and EBV-associated malignancies are often associated with a worse prognosis. Therefore, there is a clear demand for EBV-specific therapies for both prevention and treatment of viral-associated malignancies. Non-cancerous cells preferentially obtain fatty acids from dietary sources whereas cancer cells will often produce fatty acids themselves by de novo lipogenesis, often becoming dependent on the pathway for cell survival and proliferation. LMP1 and EBV-mediated B-cell growth transformation leads to induction of FASN, a key enzyme responsible for the catalysis of endogenous fatty acids. Preferential killing of LMP1-expressing B cells following inhibition of FASN suggests that targeting LMP-induced lipogenesis could be an effective strategy in treating LMP1-positive EBV-associated malignancies. Importantly, targeting unique metabolic perturbations induced by EBV could be a way to explicitly target EBV-positive malignancies and distinguish their treatment from EBV-negative counterparts.

scholarly journals Gain-of-function GABRB3 variants identified in vigabatrin-hypersensitive epileptic encephalopathies

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Nathan L Absalom ◽  
Vivian W Y Liao ◽  
Kavitha Kothur ◽  
Dinesh C Indurthi ◽  
Bruce Bennetts ◽  
...  
Keyword(s):  
De Novo ◽  
Drug Effects ◽  
Receptor Expression ◽  
Aminobutyric Acid ◽  
Loss Of Function ◽  
Molecular Phenotype ◽  
Gain Of Function ◽  
Gene Encoding ◽  
Epileptic Encephalopathies ◽  
Receptor Phenotype

Abstract Variants in the GABRB3 gene encoding the β3-subunit of the γ-aminobutyric acid type A ( receptor are associated with various developmental and epileptic encephalopathies. Typically, these variants cause a loss-of-function molecular phenotype whereby γ-aminobutyric acid has reduced inhibitory effectiveness leading to seizures. Drugs that potentiate inhibitory GABAergic activity, such as nitrazepam, phenobarbital or vigabatrin, are expected to compensate for this and thereby reduce seizure frequency. However, vigabatrin, a drug that inhibits γ-aminobutyric acid transaminase to increase tonic γ-aminobutyric acid currents, has mixed success in treating seizures in patients with GABRB3 variants: some patients experience seizure cessation, but there is hypersensitivity in some patients associated with hypotonia, sedation and respiratory suppression. A GABRB3 variant that responds well to vigabatrin involves a truncation variant (p.Arg194*) resulting in a clear loss-of-function. We hypothesized that patients with a hypersensitive response to vigabatrin may exhibit a different γ-aminobutyric acid A receptor phenotype. To test this hypothesis, we evaluated the phenotype of de novo variants in GABRB3 (p.Glu77Lys and p.Thr287Ile) associated with patients who are clinically hypersensitive to vigabatrin. We introduced the GABRB3 p.Glu77Lys and p.Thr287Ile variants into a concatenated synaptic and extrasynaptic γ-aminobutyric acid A receptor construct, to resemble the γ-aminobutyric acid A receptor expression by a patient heterozygous for the GABRB3 variant. The mRNA of these constructs was injected into Xenopus oocytes and activation properties of each receptor measured by two-electrode voltage clamp electrophysiology. Results showed an atypical gain-of-function molecular phenotype in the GABRB3 p.Glu77Lys and p.Thr287Ile variants characterized by increased potency of γ-aminobutyric acid A without change to the estimated maximum open channel probability, deactivation kinetics or absolute currents. Modelling of the activation properties of the receptors indicated that either variant caused increased chloride flux in response to low concentrations of γ-aminobutyric acid that mediate tonic currents. We therefore propose that the hypersensitivity reaction to vigabatrin is a result of GABRB3 variants that exacerbate GABAergic tonic currents and caution is required when prescribing vigabatrin. In contrast, drug strategies increasing tonic currents in loss-of-function variants are likely to be a safe and effective therapy. This study demonstrates that functional genomics can explain beneficial and adverse anti-epileptic drug effects, and propose that vigabatrin should be considered in patients with clear loss-of-function GABRB3 variants.

scholarly journals Long noncoding RNA FER1L4 promotes the malignant processes of papillary thyroid cancer by targeting the miR-612/ Cadherin 4 axis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Luyao Wu ◽  
Yu Ding ◽  
Houchao Tong ◽  
Xi Zhuang ◽  
Jingsheng Cai ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Papillary Thyroid Cancer ◽  
Noncoding Rna ◽  
Animal Experiments ◽  
Ectopic Expression ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Papillary Thyroid ◽  
Loss Of Function ◽  
Functional Roles

Abstract Background Long noncoding RNAs (lncRNAs) have emerged as crucial regulators in various cancers. However, the functional roles of most lncRNA in papillary thyroid cancer (PTC) are not detailly understood. This study aims to investigate the biological function and molecular mechanism of lncRNA Fer-1 like family member 4 (FER1L4) in PTC. Methods The expression of FER1L4 in PTC was determined via operating quantitative real-time PCR assays. Meanwhile, the clinical significance of FER1L4 in patients with PTC was described. The biological functions of FER1L4 on PTC cells were evaluated by gain and loss of function experiments. Moreover, animal experiments were performed to reveal the effect on tumor growth. Subcellular distribution of FER1L4 was determined by fluorescence in situ hybridization and subcellular localization assays. Luciferase reporter assay and RNA immunoprecipitation assay were applied to define the relationship between FER1L4, miR-612, and Cadherin 4 (CDH4). Results Upregulated expression of FER1L4 in PTC tissues was positively correlated with lymph node metastasis (P = 0.020), extrathyroidal extension (P = 0.013) and advanced TNM stages (P = 0.013). In addition, knockdown of FER1L4 suppressed PTC cell proliferation, migration, and invasion, whereas ectopic expression of FER1L4 inversely promoted these processes. Mechanistically, FER1L4 could competitively bind with miR-612 to prevent the degradation of its target gene CDH4. This condition was further confirmed in the rescue assays. Conclusions This study first demonstrates FER1L4 plays an oncogenic role in PTC via a FER1L4-miR-612-CDH4 axis and may provide new therapeutic and diagnostic targets for PTC.

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