scholarly journals The Metabolic Chemical Reporter Ac46AzGal Could Incorporate Intracellular Protein Modification in the Form of UDP-6AzGlc Mediated by OGT and Enzymes in the Leloir Pathway

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiajia Wang ◽  
Biao Dou ◽  
Lu Zheng ◽  
Wei Cao ◽  
Peiyu Dong ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Protein Modification ◽  
Time Dependent ◽  
Dependent Manner ◽  
Intracellular Protein ◽  
Galactose Metabolism ◽  
Naturally Occurring ◽  
Leloir Pathway ◽  
Chemical Reporter ◽  
Complex Glycans

Galactose is a naturally occurring monosaccharide used to build complex glycans that has not been targeted for labeling as a metabolic reporter. Here, we characterize the cellular modification of proteins by using Ac46AzGal in a dose- and time-dependent manner. It is noted that a vast majority of this labeling of Ac46AzGal occurs intracellularly in a range of mammalian cells. We also provided evidence that this labeling is dependent on not only the enzymes of OGT responsible for O-GlcNAcylation but also the enzymes of GALT and GALE in the Leloir pathway. Notably, we discover that Ac46AzGal is not the direct substrate of OGT, and the labeling results may attribute to UDP-6AzGlc after epimerization of UDP-6AzGal via GALE. Together, these discoveries support the conclusion that Ac46AzGal as an analogue of galactose could metabolically label intracellular O-glycosylation modification, raising the possibility of characterization with impaired functions of the galactose metabolism in the Leloir pathway under certain conditions, such as galactosemias.

Pseudomonas aeruginosa lectins I and II and their interaction with human airway cilia

2005 ◽  
Vol 119 (8) ◽  
pp. 595-599 ◽  
Author(s):  
Marco Mewe ◽  
Denis Tielker ◽  
Robert Schönberg ◽  
Melitta Schachner ◽  
Karl-Erich Jaeger ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Joint Action ◽  
Mammalian Cells ◽  
Time Dependent ◽  
Carbohydrate Binding ◽  
Dependent Manner ◽  
Similar Time ◽  
Airway Cilia ◽  
Kinetics Of ◽  
Ciliary Beat

The bacterium Pseudomonas aeruginosa (PA) produces two carbohydrate binding lectins, designated PA lectin-I and lectin-II (PA-IL, PA-IIL). Both lectins are used by the bacterium to adhere to the glycocalyx of mammalian cells. In addition, the lectins immobilize ciliary beat. The kinetics of ciliary beat inhibition by each individual lectin have been analysed; however, their joint action on cilia has not been reported. Here we demonstrate that PA-IL and PA-IIL inhibit ciliary beat in a similar time-dependent manner. If applied simultaneously, ciliary beat inhibition after five hours of incubation was weaker than if each lectin was applied separately. Thus it can be hypothesized that the lectins compete for the same binding site(s) of the glycocalyx. Sugar inhibition experiments demonstrate that D-galactose and L-fucose inhibit both lectins, although clear preferences of D-galactose for PA-IL and of L-fucose for PA-IIL exist. These interactions have to be kept in mind when designing sugar-based therapies.

scholarly journals The Corepressor mSin3A Regulates Phosphorylation-Induced Activation, Intranuclear Location, and Stability of AML1

2004 ◽  
Vol 24 (3) ◽  
pp. 1033-1043 ◽  
Author(s):  
Yoichi Imai ◽  
Mineo Kurokawa ◽  
Yuko Yamaguchi ◽  
Koji Izutsu ◽  
Eriko Nitta ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Protein Modification ◽  
Transcriptional Activity ◽  
Regulatory Mechanism ◽  
Dna Binding Protein ◽  
Time Dependent ◽  
Myeloid Differentiation ◽  
Dependent Manner ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal

ABSTRACT The AML1 (RUNX1) gene, one of the most frequent targets of translocations associated with human leukemias, encodes a DNA-binding protein that plays pivotal roles in myeloid differentiation through transcriptional regulation of various genes. Previously, we reported that AML1 is phosphorylated on two serine residues with dependence on activation of extracellular signal-regulated kinase, which positively regulates the transcriptional activity of AML1. Here, we demonstrate that the interaction between AML1 and the corepressor mSin3A is regulated by phosphorylation of AML1 and that release of AML1 from mSin3A induced by phosphorylation activates its transcriptional activity. Furthermore, phosphorylation of AML1 regulates its intranuclear location and disrupts colocalization of AML1 with mSin3A in the nuclear matrix. PEBP2β/CBFβ, a heterodimeric partner of AML1, was shown to play a role in protecting AML1 from proteasome-mediated degradation. We show that mSin3A also protects AML1 from proteasome-mediated degradation and that phosphorylation-induced release of AML1 from mSin3A results in degradation of AML1 in a time-dependent manner. This study provides a novel regulatory mechanism for the function of transcription factors mediated by protein modification and interaction with cofactors.

scholarly journals Cytotoxic activity of Bacillus thuringiensis Cry proteins on mammalian cells transfected with cadherin-like Cry receptor gene of Bombyx mori (silkworm)

2003 ◽  
Vol 369 (3) ◽  
pp. 697-703 ◽  
Author(s):  
Yoko TSUDA ◽  
Fumiki NAKATANI ◽  
Keiko HASHIMOTO ◽  
Satoshi IKAWA ◽  
Chikako MATSUURA ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Bombyx Mori ◽  
Mammalian Cells ◽  
Receptor Gene ◽  
Time Dependent ◽  
Hek293 Cells ◽  
Dependent Manner ◽  
Specific Receptor ◽  
Cry Proteins ◽  
Variant Alleles

Cry1Aa, an insecticidal protein produced by Bacillus thuringiensis, has been shown to bind to cadherin-like protein, BtR175, in Bombyx mori (silkworm) midgut. We previously reported three variant alleles of BtR175 (BtR175a, b and c). When transiently expressed in COS7 cells, all the three BtR175 variants bound to Cry1Aa. We stably expressed BtR175b in HEK293 cells. These BtR175b-expressing cells swelled and died in the presence of activated Cry1Aa in a dose- and time-dependent manner, showing that BtR175b itself can impart Cry1Aa-susceptibility to mammalian cells. These cells were more susceptible to Cry1Aa than to Cry1Ab and Cry1Ac. Since dispersed B. mori midgut cells were reported to be highly susceptible to Cry1Ac, this result suggested that other Cry1Ac-specific receptor(s) were simultaneously working with BtR175 in the midgut cells. Advantages are also discussed of applying these transfected mammalian cells to toxicity assays of mutant Cry proteins.

scholarly journals Modulation of p21, DAPK1 and COX-2 during the DMBA/TPA-induced mouse skin tumorigenesis and its prevention by phytic acid

2014 ◽  
Vol 2 (04) ◽  
pp. 61-67
Author(s):  
Chhaya Pandey ◽  
Rashmi Arnold ◽  
Rahasya Mani Mishra
Keyword(s):  
Phytic Acid ◽  
Methylation Status ◽  
Mouse Skin ◽  
Experimental Models ◽  
Time Dependent ◽  
Dependent Manner ◽  
Protective Effects ◽  
Skin Tumorigenesis ◽  
Naturally Occurring ◽  
Cox 2

Chemoprevention by naturally occurring agents is gaining much attention as a newer dimension in the management of cancer. Many naturally occurring agents have shown cancer chemopreventive potential in a variety of bioassay systems and animal models, having relevance to human disease. Phytic acid or Inositol hexaphosphate (IP6), an antioxidant, is a naturally occurring polyphosphorylated carbohydrate that has shown a strong anticancer activity in several experimental models. We assessed the protective effects of Phytic acid against the 7, 12-dimethylbenz [a] anthracene (DMBA)/ 12-O-tetradecanoylphorbol-13- acetate (TPA) induced mouse skin tumorigenesis at 4 and 16 weeks, the time before and after the tumor development. At molecular level we studied expression and promoter CpG methylation status of p21, DAPK1 and COX-2. Our data suggests exposure of DMBA/TPA methylated the promoter region of p21 and DAPK1 genes in time dependent manner that could be the cause of down regulation of their expression with time, which were reversed by administration of phytic acid. But we did not observe methylation in COX-2 whereas upregulation of COX-2 was observed at protein level in mice treated with DMBA followed by TPA in time dependent manner. Administration of phytic acid prevented theses DMBA/TPA induced molecular changes. Study provides a rationale for cancer chemoprevention by natural occurring compounds like Phytic acid.

The Modification and Design of Antimicrobial Peptide

2018 ◽  
Vol 24 (8) ◽  
pp. 904-910 ◽  
Author(s):  
Yidan Gao ◽  
Hengtong Fang ◽  
Lu Fang ◽  
Dawei Liu ◽  
Jinsong Liu ◽  
...  
Keyword(s):  
Chemical Modification ◽  
Antimicrobial Peptide ◽  
Protein Modification ◽  
Recent Progress ◽  
Therapeutic Agents ◽  
Manufacturing Cost ◽  
Commercial Development ◽  
Biochemical Modification ◽  
Naturally Occurring ◽  
Application Prospects

The antimicrobial peptides (AMPs) are a group of unique naturally occurring anti-microbial compounds with around 50 amino acids. It represents promising therapeutic agents to the infectious disease without concerning about drug resistance. However, commercial development of these peptides for even the simplest application has been hindered by the limitations of sources, instability, toxicity and bioavailability. To improve the properties of the artificial synthesized AMPs, the modification and design are the hotspots of the AMPs research. In fact, more than half of the known AMPs are naturally modified. In this review, two types of modification strategies, biochemical modification and chemical modification were summarized. Although, the chemical modification is versatile and direct, the manufacturing cost is greatly increased compared to the antibiotics. With the recent progress of the protein modification enzyme, the biochemical modification of the antimicrobial peptide followed by heterologous expression has great application prospects.

The Natural Flavonoid Naringenin Inhibits the Cell Growth of WilmsTumorinChildren by Suppressing TLR4/NF-κB Signaling

2020 ◽  
Vol 20 ◽  
Author(s):  
Hongtao Li ◽  
Peng Chen ◽  
Lei Chen ◽  
Xinning Wang
Keyword(s):  
Cell Growth ◽  
Western Blot ◽  
Wilms Tumor ◽  
Critical Role ◽  
Time Dependent ◽  
Luciferase Assay ◽  
Dependent Manner ◽  
Tlr4 Expression ◽  
Protein Levels

Background: Nuclear factor kappa B (NF-κB) is usually activated in Wilms tumor (WT) cells and plays a critical role in WT development. Objective: The study purpose was to screen a NF-κB inhibitor from natural product library and explore its effects on WT development. Methods: Luciferase assay was employed to assess the effects of natural chemical son NF-κB activity. CCK-8 assay was conducted to assess cell growth in response to naringenin. WT xenograft model was established to analyze the effect of naringenin in vivo. Quantitative real-time PCR and Western blot were performed to examine the mRNA and protein levels of relative genes, respectively. Results: Naringenin displayed significant inhibitory effect on NF-κB activation in SK-NEP-1 cells. In SK-NEP-1 and G-401 cells, naringenin inhibited p65 phosphorylation. Moreover, naringenin suppressed TNF-α-induced p65 phosphorylation in WT cells. Naringenin inhibited TLR4 expression at both mRNA and protein levels in WT cells. CCK-8 staining showed that naringenin inhibited cell growth of the two above WT cells in dose-and time-dependent manner, whereas Toll-like receptor 4 (TLR4) over expression partially reversed the above phenomena. Besides, naringenin suppressed WT tumor growth in dose-and time-dependent manner in vivo. Western blot found that naringenin inhibited TLR4 expression and p65 phosphorylation in WT xenograft tumors. Conclusion: Naringenin inhibits WT development viasuppressing TLR4/NF-κB signaling

scholarly journals Synthesis and Evaluation of the Antitumor Activity of Novel 1-(4-Substituted phenyl)-2-ethyl Imidazole Apoptosis Inducers In Vitro

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4293
Author(s):  
Zhen-Wang Li ◽  
Chun-Yan Zhong ◽  
Xiao-Ran Wang ◽  
Shi-Nian Li ◽  
Chun-Yuan Pan ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Tumor Cells ◽  
Antiproliferative Activity ◽  
Antitumor Agent ◽  
Positive Control ◽  
Selectivity Index ◽  
Time Dependent ◽  
Potential Candidate ◽  
Dependent Manner

Novel imidazole derivatives were designed, prepared, and evaluated in vitro for antitumor activity. The majority of the tested derivatives showed improved antiproliferative activity compared to the positive control drugs 5-FU and MTX. Among them, compound 4f exhibited outstanding antiproliferative activity against three cancer cell lines and was considerably more potent than both 5-FU and MTX. In particular, the selectivity index indicated that the tolerance of normal L-02 cells to 4f was 23–46-fold higher than that of tumor cells. This selectivity was significantly higher than that exhibited by the positive control drugs. Furthermore, compound 4f induced cell apoptosis by increasing the protein expression levels of Bax and decreasing those of Bcl-2 in a time-dependent manner. Therefore, 4f could be a potential candidate for the development of a novel antitumor agent.

scholarly journals Moxifloxacin Activates the SOS Response in Mycobacterium tuberculosis in a Dose- and Time-Dependent Manner

2021 ◽  
Vol 9 (2) ◽  
pp. 255
Author(s):  
Angelo Iacobino ◽  
Giovanni Piccaro ◽  
Manuela Pardini ◽  
Lanfranco Fattorini ◽  
Federico Giannoni
Keyword(s):  
Gene Expression ◽  
Mycobacterium Tuberculosis ◽  
Physiological State ◽  
Transcriptional Response ◽  
Sos Response ◽  
Resistant Mutant ◽  
Time Dependent ◽  
Dependent Manner ◽  
Gyra Gene ◽  
Drug Concentrations

Previous studies on Escherichia coli demonstrated that sub-minimum inhibitory concentration (MIC) of fluoroquinolones induced the SOS response, increasing drug tolerance. We characterized the transcriptional response to moxifloxacin in Mycobacterium tuberculosis. Reference strain H37Rv was treated with moxifloxacin and gene expression studied by qRT-PCR. Five SOS regulon genes, recA, lexA, dnaE2, Rv3074 and Rv3776, were induced in a dose- and time-dependent manner. A range of moxifloxacin concentrations induced recA, with a peak observed at 2 × MIC (0.25 μg/mL) after 16 h. Another seven SOS responses and three DNA repair genes were significantly induced by moxifloxacin. Induction of recA by moxifloxacin was higher in log-phase than in early- and stationary-phase cells, and absent in dormant bacilli. Furthermore, in an H37Rv fluoroquinolone-resistant mutant carrying the D94G mutation in the gyrA gene, the SOS response was induced at drug concentrations higher than the mutant MIC value. The 2 × MIC of moxifloxacin determined no significant changes in gene expression in a panel of 32 genes, except for up-regulation of the relK toxin and of Rv3290c and Rv2517c, two persistence-related genes. Overall, our data show that activation of the SOS response by moxifloxacin, a likely link to increased mutation rate and persister formation, is time, dose, physiological state and, possibly, MIC dependent.

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