scholarly journals Glycosylation: A “Last Word” in the Protein-Mediated Biomineralization Process

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 818
Author(s):  
John Spencer Evans
Keyword(s):  
Crystal Growth ◽  
Polypeptide Chain ◽  
Covalent Attachment ◽  
Matrix Assembly ◽  
Post Translational Modifications ◽  
Biomineralization Process ◽  
Different Types ◽  
Protein Functions ◽  
The Impact

Post-translational modifications are one way that biomineral-associated cells control the function and fate of proteins. Of the ten different types of post-translational modifications, one of the most interesting and complex is glycosylation, or the covalent attachment of carbohydrates to amino acid sidechains Asn, Ser, and Thr of proteins. In this review the author surveys some of the known biomineral-associated glycoproteins and summarizes recent in vitro recombinant protein experiments which test the impact of glycosylation on biomineralization protein functions, such as nucleation, crystal growth, and matrix assembly. These in vitro studies show that glycosylation does not alter the inherent function of the polypeptide chain; rather, it either accentuates or attenuates functionality. In essence, glycosylation gives the cell the “last word” as to what degree a biomineralization protein will participate in the biomineralization process.

scholarly journals A green tea polyphenol Epigallocatechin-3-gallate modulates Tau Post-translational modifications and cytoskeletal network

2020 ◽  
Author(s):  
Shweta Kishor Sonawane ◽  
Subashchandrabose Chinnathambi
Keyword(s):  
Green Tea ◽  
Advanced Glycation Endproducts ◽  
Neuroblastoma Cells ◽  
Tea Polyphenol ◽  
Advanced Glycation ◽  
Microtubule Organizing Center ◽  
Post Translational Modifications ◽  
Green Tea Polyphenol ◽  
The Impact

AbstractBackgroundAlzheimer’s disease is a type of dementia denoted by progressive neuronal death due to the accumulation of proteinaceous aggregates of Tau. Post-translational modifications like hyperphosphorylation, truncation, glycation, etc. play a pivotal role in Tau pathogenesis. Glycation of Tau aids in paired helical filament formation and abates its microtubule-binding function. The chemical modulators of Tau PTMs, such as kinase inhibitors and antibody-based therapeutics, have been developed, but natural compounds, as modulators of Tau PTMs are not much explored.MethodsWe applied biophysical and biophysical techniques like fluorescence kinetics, SDS-PAGE, western blot analysis and transmission electron microscopy to investigate the impact of EGCG on Tau glycation in vitro. The effect of glycation on cytoskeleton instability and its EGCG-mediated rescue were studied by immunofluorescence in neuroblastoma cells.ResultsEGCG inhibited methyl glyoxal (MG)-induced Tau glycation in vitro. EGCG potently inhibited MG-induced advanced glycation endproducts formation in neuroblastoma cells as well modulated the localization of AT100 phosphorylated Tau in the cells. In addition to preventing the glycation, EGCG enhanced actin-rich neuritic extensions and rescued actin and tubulin cytoskeleton severely disrupted by MG. EGCG maintained the integrity of the Microtubule Organizing Center (MTOC) stabilized microtubules by Microtubule-associated protein RP/EB family member 1 (EB1).ConclusionsWe report EGCG, a green tea polyphenol, as a modulator of in vitro methylglyoxal-induced Tau glycation and its impact on reducing advanced glycation end products in neuroblastoma cells. We unravel unprecedented function of EGCG in remodeling neuronal cytoskeletal integrity.

scholarly journals Heterologous expression and purification of recombinant human protoporphyrinogen oxidase IX: A comparative study

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259837
Author(s):  
Zora Novakova ◽  
Daria Khuntsaria ◽  
Marketa Gresova ◽  
Jana Mikesova ◽  
Barbora Havlinova ◽  
...  
Keyword(s):  
Heterologous Expression ◽  
Mammalian Cells ◽  
Specific Activity ◽  
Eukaryotic Cells ◽  
Post Translational Modifications ◽  
Protoporphyrinogen Oxidase ◽  
Intracellular Targeting ◽  
Alternative Systems ◽  
Protein Functions ◽  
The Impact

Human protoporphyrinogen oxidase IX (hPPO) is an oxygen-dependent enzyme catalyzing the penultimate step in the heme biosynthesis pathway. Mutations in the enzyme are linked to variegate porphyria, an autosomal dominant metabolic disease. Here we investigated eukaryotic cells as alternative systems for heterologous expression of hPPO, as the use of a traditional bacterial-based system failed to produce several clinically relevant hPPO variants. Using bacterially-produced hPPO, we first analyzed the impact of N-terminal tags and various detergent on hPPO yield, and specific activity. Next, the established protocol was used to compare hPPO constructs heterologously expressed in mammalian HEK293T17 and insect Hi5 cells with prokaryotic overexpression. By attaching various fusion partners at the N- and C-termini of hPPO we also evaluated the influence of the size and positioning of fusion partners on expression levels, specific activity, and intracellular targeting of hPPO fusions in mammalian cells. Overall, our results suggest that while enzymatically active hPPO can be heterologously produced in eukaryotic systems, the limited availability of the intracellular FAD co-factor likely negatively influences yields of a correctly folded protein making thus the E.coli a system of choice for recombinant hPPO overproduction. At the same time, PPO overexpression in eukaryotic cells might be preferrable in cases when the effects of post-translational modifications (absent in bacteria) on target protein functions are studied.

scholarly journals Investigating crosstalk among PTMs provides novel insight into the structural basis underlying the differential effects of Nt17 PTMs on mutant Httex1 aggregation

2021 ◽  
Author(s):  
Anass Chiki ◽  
Zhidian Zhang ◽  
Kolla Rajasekhar ◽  
Luciano A. Abriata ◽  
Iman Rostami ◽  
...  
Keyword(s):  
Inhibitory Effect ◽  
Dynamics Simulation ◽  
Helical Conformation ◽  
Structural Basis ◽  
Similar Distribution ◽  
Post Translational Modifications ◽  
Differential Effects ◽  
The Impact ◽  
Insight Into

AbstractPost-translational modifications (PTMs) within the first 17 amino acids (Nt17) of the Huntingtin protein (Htt) have been shown to inhibit the aggregation and attenuate the toxicity of mutant Htt proteins in vitro and in various models of Huntington’s disease. Our group’s previous studies suggested that the Nt17 PTM code is a combinatorial code that involves a complex interplay between different PTMs. Here, we expand on these studies by investigating the effect of methionine 8 oxidation (oxM8) and crosstalk between this PTM and either lysine 6 acetylation (AcK6) or threonine 3 phosphorylation (pT3) on the aggregation of mutant Httex1. We show that M8 oxidation delays but does not inhibit the aggregation and has no effect on the final morphologies of mutant Httex1 aggregates. This delay in aggregation kinetics could be attributed to the transient accumulation of oligomeric aggregates, which disappear upon the formation of Httex1 oxM8 fibrils. Interestingly, the presence of both oxM8 and AcK6 resulted in dramatic inhibition of Httex1 fibrillization, whereas the presence of oxM8 did not influence the aggregation inhibitory effect of pT3. To gain insight into the structural basis underlying these proteins’ aggregation properties, we investigated the impact of each PTM and the combination of these PTMs on the conformational properties of the Nt17 peptide by circular dichroism spectroscopy and molecular dynamics simulation. These studies show that M8 oxidation decreases the helicity of the Nt17 in the presence or absence of PTMs and provides novel insight into the structural basis underlying the effects of different PTMs on mutant Httex1 aggregation. PTMs that lower the mutant Httex1 aggregation rate (oxM8, AcK6/oxM8, pT3, pT3/oxM8, and phosphorylation at Serine 13) result in stabilization and increased population of a short N-terminal helix (first eight residues) in Nt17 or decreased abundance of other helical forms, including long helix and short C-terminal helix. PTMs that did not alter the aggregation of mutant Httex1 exhibit a similar distribution of helical conformation as the unmodified peptides. These results show that the relative abundance of N- vs. C-terminal helical conformations and long helices, rather than the overall helicity of Nt17, better explains the effect of different Nt17 PTMs on mutant Httex1; thus, explaining the lack of correlation between the effect of PTMs on the overall helicity of Nt17 and mutant Httex1 aggregation in vitro. Taken together, our results provide novel structural insight into the differential effects of single PTMs and crosstalk between different PTMs in regulating mutant Httex1 aggregation.TOC Figure

scholarly journals Cell Lysate Microarray for Mapping the Network of Genetic Regulators for Histone Marks

2017 ◽  
Author(s):  
Li Cheng ◽  
Cheng-xi Liu ◽  
Shuang-ying Jiang ◽  
Sha Hou ◽  
Jin-guo Huang ◽  
...  
Keyword(s):  
Temperature Sensitive ◽  
General Applicability ◽  
Post Translational Modifications ◽  
Histone Marks ◽  
Cell Lysate ◽  
Genome Wide ◽  
Protein Functions ◽  
A Cell ◽  
Global Identification ◽  
The Impact

SUMMARYProtein, as the major executer for cell progresses and functions, its abundance and the level of post-translational modifications, are tightly monitored by regulators. Genetic perturbation could help us to understand the relationships between genes and protein functions. Herein, we developed a cell lysate microarray on kilo-conditions (CLICK) from 4,837 yeast knockout (YKO) strains and 322 temperature-sensitive mutant strains to explore the impact of the genome-wide interruption on certain protein. Taking histone marks as examples, a general workflow was established for the global identification of upstream regulators. Through a single CLICK array test, we obtained a series of regulators for H3K4me3 which covers most of the known regulators in Saccharomyces cerevisiae. We also noted that several group of proteins that are linked to negatively regulation of H3K4me3. Further, we discovered that Cab4p and Cab5p, two key enzymes of CoA biosynthesis, play central roles in histone acylation. Because of its general applicability, CLICK array could be easily adopted to rapid and global identification of upstream protein/enzyme(s) that regulate/modify the level of a protein or the posttranslational modification of a non-histone protein.

scholarly journals Iodothyronine deiodinase structure and function: from ascidians to humans

2012 ◽  
Vol 215 (2) ◽  
pp. 189-206 ◽  
Author(s):  
Veerle M Darras ◽  
Stijn L J Van Herck
Keyword(s):  
Developmental Stages ◽  
The Body ◽  
Thyroid Status ◽  
Iodothyronine Deiodinase ◽  
Relative Contribution ◽  
Iodothyronine Deiodinases ◽  
Different Types ◽  
And Function ◽  
The Impact

Iodothyronine deiodinases are important mediators of thyroid hormone (TH) action. They are present in tissues throughout the body where they catalyse 3,5,3′-triiodothyronine (T3) production and degradation via, respectively, outer and inner ring deiodination. Three different types of iodothyronine deiodinases (D1, D2 and D3) have been identified in vertebrates from fish to mammals. They share several common characteristics, including a selenocysteine residue in their catalytic centre, but show also some type-specific differences. These specific characteristics seem very well conserved for D2 and D3, while D1 shows more evolutionary diversity related to itsKm, 6-n-propyl-2-thiouracil sensitivity and dependence on dithiothreitol as a cofactorin vitro. The three deiodinase types have an impact on systemic T3levels and they all contribute directly or indirectly to intracellular T3availability in different tissues. The relative contribution of each of them, however, varies amongst species, developmental stages and tissues. This is especially true for amphibians, where the impact of D1 may be minimal. D2 and D3 expression and activity respond to thyroid status in an opposite and conserved way, while the response of D1 is variable, especially in fish. Recently, a number of deiodinases have been cloned from lower chordates. Both urochordates and cephalochordates possess selenodeiodinases, although they cannot be classified in one of the three vertebrate types. In addition, the cephalochordate amphioxus also expresses a non-selenodeiodinase. Finally, deiodinase-like sequences have been identified in the genome of non-deuterostome organisms, suggesting that deiodination of externally derived THs may even be functionally relevant in a wide variety of invertebrates.

scholarly journals The Impact of Autoantibodies on IVF Treatment and Outcome: A Systematic Review

2019 ◽  
Vol 20 (4) ◽  
pp. 892 ◽  
Author(s):  
Mara Simopoulou ◽  
Konstantinos Sfakianoudis ◽  
Evangelos Maziotis ◽  
Sokratis Grigoriadis ◽  
Polina Giannelou ◽  
...  
Keyword(s):  
Systematic Review ◽  
Inclusion Criteria ◽  
Vitro Fertilization ◽  
Different Types ◽  
Significant Research ◽  
Central Database ◽  
The Impact

The role of autoantibodies in in vitro fertilization (IVF) has been discussed for almost three decades. Nonetheless, studies are still scarce and widely controversial. The aim of this study is to provide a comprehensive systematic review on the possible complications associated to autoantibodies (AA) impeding the chances of a successful IVF cycle. An Embase, PubMed/Medline and Cochrane Central Database search was performed on 1 December 2018, from 2006 until that date. From the 598 articles yielded in the search only 44 relevant articles ultimately fulfilled the inclusion criteria and were qualitatively analyzed. Five subsets of results were identified, namely, thyroid related AA, anti-phospholipid antibodies, anti-nuclear antibodies, AA affecting the reproductive system and AA related to celiac disease. It may be implied that the majority of auto-antibodies exert a statistically significant effect on miscarriage rates, whereas the effects on clinical pregnancy and live birth rates differ according to the type of auto-antibodies. While significant research is performed in the field, the quality of evidence provided is still low. The conduction of well-designed prospective cohort studies is an absolute necessity in order to define the impact of the different types of autoantibodies on IVF outcome.

The impact of different types of anesthesia on in vitro fertilization-embryo transfer treatment outcome

1995 ◽  
Vol 12 (10) ◽  
pp. 678-682 ◽  
Author(s):  
Ofer Gonen ◽  
Adrian Shulman ◽  
Yehudit Ghetler ◽  
Arieh Shapiro ◽  
Robert Judeiken ◽  
...  
Keyword(s):  
Treatment Outcome ◽  
In Vitro Fertilization ◽  
Embryo Transfer ◽  
Vitro Fertilization ◽  
Different Types ◽  
The Impact

scholarly journals Comparison of cytotoxicity effects induced by four different types of nanoparticles in human corneal and conjunctival epithelial cells

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiangzhe Li ◽  
Boram Kang ◽  
Youngsub Eom ◽  
Jingxiang Zhong ◽  
Hyung Keun Lee ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Ocular Surface ◽  
Protective Role ◽  
Toxic Effects ◽  
Chemical Components ◽  
Different Types ◽  
Cytotoxicity Effects ◽  
The Impact ◽  
Conjunctival Epithelial Cells

AbstractThe impact of particulate matter (PM) on ocular surface health has attracted increased attention in recent years. Previous studies have reported that differences in the chemical composition of PM can affect the toxicological response. However, available information on the toxic effects of chemical components of PM on the ocular surface is insufficient. In this paper, we aimed to investigate the toxicity effects of chemical components of PM on the ocular surface, focusing on the effects of four different types of nanoparticles (NPs) in human corneal epithelial cells (HCECs) and human conjunctival epithelial cells (HCjECs), which include titanium dioxide (TiO2), carbon black (CB), zinc dioxide (ZnO), and silicon dioxide (SiO2). We found that the in vitro cytotoxic effects of CB, ZnO, and SiO2 NPs are dependent on particle properties and cell type as well as the exposure concentration and time. Here, the order of increasing toxicity was SiO2 → CB → ZnO, while TiO2 demonstrated no toxicity. Moreover, toxic effects appearing more severe in HCECs than HCjECs. Reactive oxygen species (ROS)-mediated oxidative stress plays a key role in the toxicity of these three NPs in HCECs and HCjECs, leading to apoptosis and mitochondrial damage, which are also important contributors to aging. Sirtuin1 (SIRT1) as an NAD+-dependent protein deacetylase that seems to play a potential protective role in this process. These findings implied that ROS and/or SIRT1 may become a potential target of clinical treatment of PM- or NP-related ocular surface diseases.

scholarly journals Temperature Values Variability in Piezoelectric Implant Site Preparation: Differences between Cortical and Corticocancellous Bovine Bone

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Luca Lamazza ◽  
Girolamo Garreffa ◽  
Domenica Laurito ◽  
Marco Lollobrigida ◽  
Luigi Palmieri ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Site Preparation ◽  
Bovine Bone ◽  
Standardized Protocol ◽  
Different Types ◽  
Group A ◽  
Implant Site Preparation ◽  
The Impact ◽  
Drilling Time

Purpose. Various parameters can influence temperature rise and detection during implant site preparation. The aim of this study is to investigate local temperature values in cortical and corticocancellous bovine bone during early stages of piezoelectric implant site preparation.Materials and Methods. 20 osteotomies were performed using a diamond tip (IM1s, Mectron Medical Technology, Carasco, Italy) on two different types of bovine bone samples, cortical and corticocancellous, respectively. A standardized protocol was designed to provide constant working conditions. Temperatures were measured in real time at a fixed position by a fiber optic thermometer.Results. Significantly higher drilling time (154.90 sec versus 99.00 sec;p<0.0001) and temperatures (39.26°C versus 34.73°C;p=0.043) were observed in the cortical group compared to the corticocancellous group. A remarkable variability of results characterized the corticocancellous blocks as compared to the blocks of pure cortical bone.Conclusion. Bone samples can influence heat generation duringin vitroimplant site preparation. When compared to cortical bone, corticocancellous samples present more variability in temperature values. Even controlling most experimental factors, the impact of bone samples still remains one of the main causes of temperature variability.

scholarly journals MPLEx: a Robust and Universal Protocol for Single-Sample Integrative Proteomic, Metabolomic, and Lipidomic Analyses

mSystems ◽  
2016 ◽  
Vol 1 (3) ◽  
Author(s):  
Ernesto S. Nakayasu ◽  
Carrie D. Nicora ◽  
Amy C. Sims ◽  
Kristin E. Burnum-Johnson ◽  
Young-Mo Kim ◽  
...  
Keyword(s):  
Systems Biology ◽  
Organic Solvent ◽  
Extraction Method ◽  
Biological Pathways ◽  
Epithelial Cell Line ◽  
Broad Applicability ◽  
Different Types ◽  
The Impact ◽  
Molecule Type

ABSTRACT In systems biology studies, the integration of multiple omics measurements (i.e., genomics, transcriptomics, proteomics, metabolomics, and lipidomics) has been shown to provide a more complete and informative view of biological pathways. Thus, the prospect of extracting different types of molecules (e.g., DNAs, RNAs, proteins, and metabolites) and performing multiple omics measurements on single samples is very attractive, but such studies are challenging due to the fact that the extraction conditions differ according to the molecule type. Here, we adapted an organic solvent-based extraction method that demonstrated broad applicability and robustness, which enabled comprehensive proteomics, metabolomics, and lipidomics analyses from the same sample. Integrative multi-omics analyses can empower more effective investigation and complete understanding of complex biological systems. Despite recent advances in a range of omics analyses, multi-omic measurements of the same sample are still challenging and current methods have not been well evaluated in terms of reproducibility and broad applicability. Here we adapted a solvent-based method, widely applied for extracting lipids and metabolites, to add proteomics to mass spectrometry-based multi-omics measurements. The metabolite, protein, and lipid extraction (MPLEx) protocol proved to be robust and applicable to a diverse set of sample types, including cell cultures, microbial communities, and tissues. To illustrate the utility of this protocol, an integrative multi-omics analysis was performed using a lung epithelial cell line infected with Middle East respiratory syndrome coronavirus, which showed the impact of this virus on the host glycolytic pathway and also suggested a role for lipids during infection. The MPLEx method is a simple, fast, and robust protocol that can be applied for integrative multi-omic measurements from diverse sample types (e.g., environmental, in vitro, and clinical). IMPORTANCE In systems biology studies, the integration of multiple omics measurements (i.e., genomics, transcriptomics, proteomics, metabolomics, and lipidomics) has been shown to provide a more complete and informative view of biological pathways. Thus, the prospect of extracting different types of molecules (e.g., DNAs, RNAs, proteins, and metabolites) and performing multiple omics measurements on single samples is very attractive, but such studies are challenging due to the fact that the extraction conditions differ according to the molecule type. Here, we adapted an organic solvent-based extraction method that demonstrated broad applicability and robustness, which enabled comprehensive proteomics, metabolomics, and lipidomics analyses from the same sample. Author Video: An author video summary of this article is available.

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