scholarly journals The development of a molecular toolbox to examine the role of protein O-mannosylation in actinobacteria

2021 ◽  
Author(s):  
Nakita Buenbrazo
Keyword(s):  
Functional Role ◽  
Protein Modification ◽  
Cell Function ◽  
Protein Glycosylation ◽  
Covalent Attachment ◽  
Cell Defense ◽  
Domains Of Life ◽  
Cell Processes

Protein glycosylation is the most abundant and diverse protein modification that occurs in all domains of life. It is defined as the covalent attachment of a carbohydrate moiety to a specific amino acid on a target protein. The functional role of this attachment is implicated in and spans various cell processes from cell signaling, cell defense, and pathogenesis – to name a few. A specific type of protein glycosylation, called protein O-mannosylation (POM) is a process found to be conserved from bacteria to man. In humans, POM is required for healthy cell function, and the absence of POM can cause fatal diseases. Certain prokaryotic species possess a related POM system, but it is poorly understood. It is our hypothesis that the analysis of the POM system in simpler organisms can aid in the characterization of this process and the functional role of the mannosylated proteins that are produced. However, the protocols to prove this theory do not yet exist. This thesis establishes a collection of developed protocols that can be used to characterize the POM systems from gram-positive species Corynebacterium glutamicum and Cellulomonas fimi. In addition the first ever evidence of a C. fimi glycoprotein being glycosylated by the endogenous C. glutamicum POM system is provided.

scholarly journals The development of a molecular toolbox to examine the role of protein O-mannosylation in actinobacteria

2021 ◽  
Author(s):  
Nakita Buenbrazo
Keyword(s):  
Functional Role ◽  
Protein Modification ◽  
Cell Function ◽  
Protein Glycosylation ◽  
Covalent Attachment ◽  
Cell Defense ◽  
Domains Of Life ◽  
Cell Processes

Protein glycosylation is the most abundant and diverse protein modification that occurs in all domains of life. It is defined as the covalent attachment of a carbohydrate moiety to a specific amino acid on a target protein. The functional role of this attachment is implicated in and spans various cell processes from cell signaling, cell defense, and pathogenesis – to name a few. A specific type of protein glycosylation, called protein O-mannosylation (POM) is a process found to be conserved from bacteria to man. In humans, POM is required for healthy cell function, and the absence of POM can cause fatal diseases. Certain prokaryotic species possess a related POM system, but it is poorly understood. It is our hypothesis that the analysis of the POM system in simpler organisms can aid in the characterization of this process and the functional role of the mannosylated proteins that are produced. However, the protocols to prove this theory do not yet exist. This thesis establishes a collection of developed protocols that can be used to characterize the POM systems from gram-positive species Corynebacterium glutamicum and Cellulomonas fimi. In addition the first ever evidence of a C. fimi glycoprotein being glycosylated by the endogenous C. glutamicum POM system is provided.

scholarly journals Glucose autoxidation and protein modification. The potential role of ‘autoxidative glycosylation’ in diabetes

1987 ◽  
Vol 245 (1) ◽  
pp. 243-250 ◽  
Author(s):  
S P Wolff ◽  
R T Dean
Keyword(s):  
Protein Modification ◽  
Potential Role ◽  
Chelating Agent ◽  
Tryptophan Fluorescence ◽  
Protein Glycosylation ◽  
Covalent Attachment ◽  
Amino Groups ◽  
Tryptophan Fluorescence Quenching

Monosaccharide autoxidation (a transition metal-catalysed process that generates H2O2 and ketoaldehydes) appears to contribute to protein modification by glucose in vitro. The metal-chelating agent diethylenetriaminepenta-acetic acid (DETAPAC), which inhibits glucose autoxidation, also reduces the covalent attachment of glucose to bovine serum albumin. A maximal 45% inhibition of covalent attachment was observed, but this varied with glucose and DETAPAC concentrations in a complex fashion, suggesting at least two modes of attachment. The extent of inhibition of the metal-catalysed pathway correlated with the extent of inhibition of glycosylation-associated chromo- and fluorophore development. DETAPAC also inhibited tryptophan fluorescence quenching associated with glycosylation. Conversely, ketoaldehydes analogous to those produced by glucose autoxidation, but generated by 60Co irradiation, bound avidly to albumin and accelerated browning reactions. It is therefore suggested that a component of protein glycosylation is dependent upon glucose autoxidation and subsequent covalent attachment of ketoaldehydes. The process of glucose autoxidation, or ketoaldehydes derived therefrom, appear to be important in chromophoric and fluorophoric alterations. It is noted, consistent with these observations, that the chemical evidence for the currently accepted ‘Amadori’ product derived from the reaction of glucose with protein amino groups is consistent also with the structure expected for the attachment of a glucose-derived ketoaldehyde to protein. The concept of ‘autoxidative glycosylation’ is briefly discussed in relation to oxidative stress in diabetes mellitus.

Structural and Thermodynamic Characterization of theEscherichia coliRelBE Toxin−Antitoxin System:  Indication for a Functional Role of Differential Stability†

Biochemistry ◽  
2007 ◽  
Vol 46 (43) ◽  
pp. 12152-12163 ◽  
Author(s):  
Izhack Cherny ◽  
Martin Overgaard ◽  
Jonas Borch ◽  
Yaron Bram ◽  
Kenn Gerdes ◽  
...  
Keyword(s):  
Functional Role ◽  
Thermodynamic Characterization ◽  
Differential Stability

scholarly journals Functional Role of FcγRIIB in the Regulation of Mesenchymal Stem Cell Function

2016 ◽  
Vol 13 (2) ◽  
pp. 154-160 ◽  
Author(s):  
Tianyi Zhu ◽  
Ruohua Chen ◽  
Zeng Li ◽  
Jun Tian ◽  
Changwen Deng ◽  
...  
Keyword(s):  
Stem Cell ◽  
Mesenchymal Stem Cell ◽  
Functional Role ◽  
Cell Function

scholarly journals The Hitchhiker's guide to glycoproteomics

2021 ◽  
Author(s):  
Tiago Oliveira ◽  
Morten Thaysen-Andersen ◽  
Nicolle H. Packer ◽  
Daniel Kolarich
Keyword(s):  
Functional Analysis ◽  
Cell Function ◽  
Prognostic Biomarker ◽  
Protein Glycosylation ◽  
Life Changes ◽  
Carrier Proteins ◽  
Post Translational Modifications ◽  
Starting Point ◽  
Domains Of Life ◽  
The Common

Protein glycosylation is one of the most common post-translational modifications that are essential for cell function across all domains of life. Changes in glycosylation are considered a hallmark of many diseases, thus making glycoproteins important diagnostic and prognostic biomarker candidates and therapeutic targets. Glycoproteomics, the study of glycans and their carrier proteins in a system-wide context, is becoming a powerful tool in glycobiology that enables the functional analysis of protein glycosylation. This ‘Hitchhiker's guide to glycoproteomics’ is intended as a starting point for anyone who wants to explore the emerging world of glycoproteomics. The review moves from the techniques that have been developed for the characterisation of single glycoproteins to technologies that may be used for a successful complex glycoproteome characterisation. Examples of the variety of approaches, methodologies, and technologies currently used in the field are given. This review introduces the common strategies to capture glycoprotein-specific and system-wide glycoproteome data from tissues, body fluids, or cells, and a perspective on how integration into a multi-omics workflow enables a deep identification and characterisation of glycoproteins — a class of biomolecules essential in regulating cell function.

scholarly journals Characterization of bacterial communities of rhizosphere and rhizoplane of Early Zhukovsky potato

2020 ◽  
Vol 222 ◽  
pp. 02050
Author(s):  
Marat Lutfulin ◽  
Darya Zaripova ◽  
Oksana Moiseeva ◽  
Semen Vologin ◽  
Ayslu Mardanova
Keyword(s):  
Bacterial Communities ◽  
Functional Role ◽  
Agricultural Crop ◽  
Potato Root ◽  
Bacterial Microbiota ◽  
16S R Rna ◽  
Significant Difference ◽  
Dominant Bacteria

Identification of patterns of formation of bacterial communities of the rhizosphere and rhizoplane of potato (Solanum tuberosum L.), the most important agricultural crop, is necessary for the introduction and maintenance of sustainable organic farming. The purpose of this work was the study of the biodiversity of the bacterial microbiota of the rhizosphere and rhizoplane of Early Zhukovsky potato, cultivated on gray forest soils. Comparative analysis based on sequencing of the 16S R RNA gene showed a significant difference in the representation of different groups of bacteria in these potato root compartments. Thus, the proportions of the dominant bacteria in the rhizosphere and rhizoplane of the Proteobacteria phylum reach 47.66% ± 7.22 % and 86.35 % ± 0.53%, respectively (P < 0.05). In contrast, the representation of phylum Bacteroidetes and Firmicutes in the rhizosphere is significantly higher and reaches 41.45 % ± 10.42% and 6.49 % ± 3.23%, respectively, compared to the rhizoplane (7.84 % ± 1.24 % and 0.43 % ± 0.48 %, (P < 0.05). At the same time, Actinobacteria phylum bacteria are present in both compartments in approximately equal amounts (4.40 % ± 1.81% in the rhizosphere and 5.37 % ± 1.42% in the rhizoplane). Thus, it was found that potato forms different bacterial communities in the rhizosphere and rhizoplane in quantitative proportions, which is probably determined by the functional role of these microorganisms in the plant physiology.

scholarly journals The Close Linkage between Nutrition and Environment through Biodiversity and Sustainability: Local Foods, Traditional Recipes, and Sustainable Diets

2019 ◽  
Vol 11 (10) ◽  
pp. 2876 ◽  
Author(s):  
Alessandra Durazzo
Keyword(s):  
Dietary Patterns ◽  
Functional Role ◽  
Close Correlation ◽  
Close Linkage ◽  
Local Foods ◽  
Special Issue ◽  
Sustainable Diets ◽  
Potential Benefits

This special issue, “The Close Linkage between Nutrition and Environment through Biodiversity and Sustainability: Local Foods, Traditional Recipes, and Sustainable Diets” is focused on the close correlation between the potential benefits and “functional role” of a food and the territory, including papers on the characterization of local foods and traditional recipes, on the promotion of traditional dietary patterns and sustainable diets.

scholarly journals Structural Insight into the Mechanism of N-Linked Glycosylation by Oligosaccharyltransferase

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 624 ◽  
Author(s):  
Smita Mohanty ◽  
Bharat P Chaudhary ◽  
David Zoetewey
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Modification ◽  
Cell Communication ◽  
Reticulum Cell ◽  
Enzyme Complex ◽  
Single Polypeptide Chain ◽  
Domains Of Life ◽  
And Function ◽  
Insight Into

Asparagine-linked glycosylation, also known as N-linked glycosylation is an essential and highly conserved post-translational protein modification that occurs in all three domains of life. This modification is essential for specific molecular recognition, protein folding, sorting in the endoplasmic reticulum, cell–cell communication, and stability. Defects in N-linked glycosylation results in a class of inherited diseases known as congenital disorders of glycosylation (CDG). N-linked glycosylation occurs in the endoplasmic reticulum (ER) lumen by a membrane associated enzyme complex called the oligosaccharyltransferase (OST). In the central step of this reaction, an oligosaccharide group is transferred from a lipid-linked dolichol pyrophosphate donor to the acceptor substrate, the side chain of a specific asparagine residue of a newly synthesized protein. The prokaryotic OST enzyme consists of a single polypeptide chain, also known as single subunit OST or ssOST. In contrast, the eukaryotic OST is a complex of multiple non-identical subunits. In this review, we will discuss the biochemical and structural characterization of the prokaryotic, yeast, and mammalian OST enzymes. This review explains the most recent high-resolution structures of OST determined thus far and the mechanistic implication of N-linked glycosylation throughout all domains of life. It has been shown that the ssOST enzyme, AglB protein of the archaeon Archaeoglobus fulgidus, and the PglB protein of the bacterium Campylobactor lari are structurally and functionally similar to the catalytic Stt3 subunit of the eukaryotic OST enzyme complex. Yeast OST enzyme complex contains a single Stt3 subunit, whereas the human OST complex is formed with either STT3A or STT3B, two paralogues of Stt3. Both human OST complexes, OST-A (with STT3A) and OST-B (containing STT3B), are involved in the N-linked glycosylation of proteins in the ER. The cryo-EM structures of both human OST-A and OST-B complexes were reported recently. An acceptor peptide and a donor substrate (dolichylphosphate) were observed to be bound to the OST-B complex whereas only dolichylphosphate was bound to the OST-A complex suggesting disparate affinities of two OST complexes for the acceptor substrates. However, we still lack an understanding of the independent role of each eukaryotic OST subunit in N-linked glycosylation or in the stabilization of the enzyme complex. Discerning the role of each subunit through structure and function studies will potentially reveal the mechanistic details of N-linked glycosylation in higher organisms. Thus, getting an insight into the requirement of multiple non-identical subunits in the N-linked glycosylation process in eukaryotes poses an important future goal.

The new world of inorganic polyphosphates

2016 ◽  
Vol 44 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Cristina Azevedo ◽  
Adolfo Saiardi
Keyword(s):  
Protein Modification ◽  
Biochemical Characterization ◽  
Covalent Attachment ◽  
Detection Methods ◽  
Inorganic Polyphosphate ◽  
Post Translational Modifications ◽  
Topoisomerase 1 ◽  
Lysine Residues ◽  
Acidic Conditions

Post-translational modifications (PTMs) add regulatory features to proteins that help establish the complex functional networks that make up higher organisms. Advances in analytical detection methods have led to the identification of more than 200 types of PTMs. However, some modifications are unstable under the present detection methods, anticipating the existence of further modifications and a much more complex map of PTMs. An example is the recently discovered protein modification polyphosphorylation. Polyphosphorylation is mediated by inorganic polyphosphate (polyP) and represents the covalent attachment of this linear polymer of orthophosphate to lysine residues in target proteins. This modification has eluded MS analysis as both polyP itself and the phosphoramidate bonds created upon its reaction with lysine residues are highly unstable in acidic conditions. Polyphosphorylation detection was only possible through extensive biochemical characterization. Two targets have been identified: nuclear signal recognition 1 (Nsr1) and its interacting partner, topoisomerase 1 (Top1). Polyphosphorylation occurs within a conserved N-terminal polyacidic serine (S) and lysine (K) rich (PASK) cluster. It negatively regulates Nsr1–Top1 interaction and impairs Top1 enzymatic activity, namely relaxing supercoiled DNA. Modulation of cellular levels of polyP regulates Top1 activity by modifying its polyphosphorylation status. Here we discuss the significance of the recently identified new role of inorganic polyP.

scholarly journals Protein O-GlcNAcylation: a new signaling paradigm for the cardiovascular system

2009 ◽  
Vol 296 (1) ◽  
pp. H13-H28 ◽  
Author(s):  
Boglarka Laczy ◽  
Bradford G. Hill ◽  
Kai Wang ◽  
Andrew J. Paterson ◽  
C. Roger White ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Cardiovascular System ◽  
Protein Modification ◽  
Cell Function ◽  
Cardiovascular Function ◽  
Cardiovascular Complications ◽  
Protective Mechanisms ◽  
Cytoplasmic Proteins ◽  
Present Understanding

The posttranslational modification of serine and threonine residues of nuclear and cytoplasmic proteins by the O-linked attachment of the monosaccharide β- N-acetylglucosamine ( O-GlcNAc) is a highly dynamic and ubiquitous protein modification. Protein O-GlcNAcylation is rapidly emerging as a key regulator of critical biological processes including nuclear transport, translation and transcription, signal transduction, cytoskeletal reorganization, proteasomal degradation, and apoptosis. Increased levels of O-GlcNAc have been implicated as a pathogenic contributor to glucose toxicity and insulin resistance, which are both major hallmarks of diabetes mellitus and diabetes-related cardiovascular complications. Conversely, there is a growing body of data demonstrating that the acute activation of O-GlcNAc levels is an endogenous stress response designed to enhance cell survival. Reports on the effect of altered O-GlcNAc levels on the heart and cardiovascular system have been growing rapidly over the past few years and have implicated a role for O-GlcNAc in contributing to the adverse effects of diabetes on cardiovascular function as well as mediating the response to ischemic injury. Here, we summarize our present understanding of protein O-GlcNAcylation and its effect on the regulation of cardiovascular function. We examine the pathways regulating protein O-GlcNAcylation and discuss, in more detail, our understanding of the role of O-GlcNAc in both mediating the adverse effects of diabetes as well as its role in mediating cellular protective mechanisms in the cardiovascular system. In addition, we also explore the parallels between O-GlcNAc signaling and redox signaling, as an alternative paradigm for understanding the role of O-GlcNAcylation in regulating cell function.

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