scholarly journals Discovery of indole-modified aptamers for highly specific recognition of protein glycoforms

2021 ◽  
Author(s):  
Alex M. Yoshikawa ◽  
Alexandra Rangel ◽  
Trevor Feagin ◽  
Elizabeth M. Chun ◽  
Leighton Wan ◽  
...  

AbstractGlycosylation is one of the most abundant forms of post-translational modification, and can have a profound impact on a wide range of biological processes and diseases. Unfortunately, efforts to characterize such modifications in the context of basic and clinical research are severely hampered by the lack of affinity reagents that can differentiate protein glycoforms. This lack of reagents is largely due to the challenges associated with generating affinity reagents that can bind to particular glycan epitopes with robust affinity and specificity. In this work, we use a fluorescence-activated cell sorting (FACS)-based approach to generate and screen aptamers with indole-modified bases in an effort to isolate reagents that can differentiate between protein glycoforms. Using this approach, we were able to select multiple aptamers that exhibit strong selectivity for specific glycoforms of two different proteins, with the capacity to discriminate between molecules with identical tertiary structures that differ only in terms of their glycan modifications.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alex M. Yoshikawa ◽  
Alexandra Rangel ◽  
Trevor Feagin ◽  
Elizabeth M. Chun ◽  
Leighton Wan ◽  
...  

AbstractGlycosylation is one of the most abundant forms of post-translational modification, and can have a profound impact on a wide range of biological processes and diseases. Unfortunately, efforts to characterize the biological function of such modifications have been greatly hampered by the lack of affinity reagents that can differentiate protein glycoforms with robust affinity and specificity. In this work, we use a fluorescence-activated cell sorting (FACS)-based approach to generate and screen aptamers with indole-modified bases, which are capable of recognizing and differentiating between specific protein glycoforms. Using this approach, we were able to select base-modified aptamers that exhibit strong selectivity for specific glycoforms of two different proteins. These aptamers can discriminate between molecules that differ only in their glycan modifications, and can also be used to label glycoproteins on the surface of cultured cells. We believe our strategy should offer a generally-applicable approach for developing useful reagents for glycobiology research.


2019 ◽  
Vol 48 (1) ◽  
pp. 281-290 ◽  
Author(s):  
Niall J. Fraser ◽  
Jacqueline Howie ◽  
Krzysztof J. Wypijewski ◽  
William Fuller

The post-translational modification protein S-acylation (commonly known as palmitoylation) plays a critical role in regulating a wide range of biological processes including cell growth, cardiac contractility, synaptic plasticity, endocytosis, vesicle trafficking, membrane transport and biased-receptor signalling. As a consequence, zDHHC-protein acyl transferases (zDHHC-PATs), enzymes that catalyse the addition of fatty acid groups to specific cysteine residues on target proteins, and acyl proteins thioesterases, proteins that hydrolyse thioester linkages, are important pharmaceutical targets. At present, no therapeutic drugs have been developed that act by changing the palmitoylation status of specific target proteins. Here, we consider the role that palmitoylation plays in the development of diseases such as cancer and detail possible strategies for selectively manipulating the palmitoylation status of specific target proteins, a necessary first step towards developing clinically useful molecules for the treatment of disease.


Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 869 ◽  
Author(s):  
Piby Paul ◽  
Manikandan Muthu ◽  
Yojitha Chilukuri ◽  
Steve W. Haga ◽  
Sechul Chun ◽  
...  

Proteomics and phosphoproteomics have been emerging as new dimensions of omics. Phosphorylation has a profound impact on the biological functions and applications of proteins. It influences everything from intrinsic activity and extrinsic executions to cellular localization. This post-translational modification has been subjected to detailed study and has been an object of analytical curiosity with the advent of faster instrumentation. The major strength of phosphoproteomic research lies in the fact that it gives an overall picture of the workforce of the cell. Phosphoproteomics gives deeper insights into understanding the mechanism behind development and progression of a disease. This review for the first time consolidates the list of existing bioinformatics tools developed for phosphoproteomics. The gap between development of bioinformatics tools and their implementation in clinical research is highlighted. The challenge facing progress is ideally believed to be the interdisciplinary arena this field of research is associated with. For meaningful solutions and deliverables, these tools need to be implemented in clinical studies for obtaining answers to pharmacodynamic questions, saving time, costs and energy. This review hopes to invoke some thought in this direction.


2019 ◽  
Vol 23 (15) ◽  
pp. 1663-1670 ◽  
Author(s):  
Chunyan Ao ◽  
Shunshan Jin ◽  
Yuan Lin ◽  
Quan Zou

Protein methylation is an important and reversible post-translational modification that regulates many biological processes in cells. It occurs mainly on lysine and arginine residues and involves many important biological processes, including transcriptional activity, signal transduction, and the regulation of gene expression. Protein methylation and its regulatory enzymes are related to a variety of human diseases, so improved identification of methylation sites is useful for designing drugs for a variety of related diseases. In this review, we systematically summarize and analyze the tools used for the prediction of protein methylation sites on arginine and lysine residues over the last decade.


2021 ◽  
Vol 22 (2) ◽  
pp. 791
Author(s):  
Qi Liu ◽  
Bayonle Aminu ◽  
Olivia Roscow ◽  
Wei Zhang

Tumor microenvironments are composed of a myriad of elements, both cellular (immune cells, cancer-associated fibroblasts, mesenchymal stem cells, etc.) and non-cellular (extracellular matrix, cytokines, growth factors, etc.), which collectively provide a permissive environment enabling tumor progression. In this review, we focused on the regulation of tumor microenvironment through ubiquitination. Ubiquitination is a reversible protein post-translational modification that regulates various key biological processes, whereby ubiquitin is attached to substrates through a catalytic cascade coordinated by multiple enzymes, including E1 ubiquitin-activating enzymes, E2 ubiquitin-conjugating enzymes and E3 ubiquitin ligases. In contrast, ubiquitin can be removed by deubiquitinases in the process of deubiquitination. Here, we discuss the roles of E3 ligases and deubiquitinases as modulators of both cellular and non-cellular components in tumor microenvironment, providing potential therapeutic targets for cancer therapy. Finally, we introduced several emerging technologies that can be utilized to develop effective therapeutic agents for targeting tumor microenvironment.


2021 ◽  
Author(s):  
Ebru Sahin Kehribar ◽  
Musa E İsilak ◽  
Eray U. Bozkurt ◽  
Jozef Adamcik ◽  
Raffaele Mezzenga ◽  
...  

Glycosylation is a crucial post-translational modification for a wide range of functionalities. Adhesive protein-based biomaterials in nature rely on heavily glycosylated proteins such as spider silk and mussel adhesive proteins....


2021 ◽  
Vol 22 (9) ◽  
pp. 4546
Author(s):  
Shiyao Chen ◽  
Yunqi Liu ◽  
Huchen Zhou

Ubiquitylation and deubiquitylation are reversible protein post-translational modification (PTM) processes involving the regulation of protein degradation under physiological conditions. Loss of balance in this regulatory system can lead to a wide range of diseases, such as cancer and inflammation. As the main members of the deubiquitinases (DUBs) family, ubiquitin-specific peptidases (USPs) are closely related to biological processes through a variety of molecular signaling pathways, including DNA damage repair, p53 and transforming growth factor-β (TGF-β) pathways. Over the past decade, increasing attention has been drawn to USPs as potential targets for the development of therapeutics across diverse therapeutic areas. In this review, we summarize the crucial roles of USPs in different signaling pathways and focus on advances in the development of USP inhibitors, as well as the methods of screening and identifying USP inhibitors.


2021 ◽  
Vol 7 (5) ◽  
pp. 328
Author(s):  
María Dolores Pejenaute-Ochoa ◽  
Carlos Santana-Molina ◽  
Damien P. Devos ◽  
José Ignacio Ibeas ◽  
Alfonso Fernández-Álvarez

Protein O-mannosyltransferases (Pmts) comprise a group of proteins that add mannoses to substrate proteins at the endoplasmic reticulum. This post-translational modification is important for the faithful transfer of nascent glycoproteins throughout the secretory pathway. Most fungi genomes encode three O-mannosyltransferases, usually named Pmt1, Pmt2, and Pmt4. In pathogenic fungi, Pmts, especially Pmt4, are key factors for virulence. Although the importance of Pmts for fungal pathogenesis is well established in a wide range of pathogens, questions remain regarding certain features of Pmts. For example, why does the single deletion of each pmt gene have an asymmetrical impact on host colonization? Here, we analyse the origin of Pmts in fungi and review the most important phenotypes associated with Pmt mutants in pathogenic fungi. Hence, we highlight the enormous relevance of these glycotransferases for fungal pathogenic development.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Shao-Zhen Lin ◽  
Wu-Yang Zhang ◽  
Dapeng Bi ◽  
Bo Li ◽  
Xi-Qiao Feng

AbstractInvestigation of energy mechanisms at the collective cell scale is a challenge for understanding various biological processes, such as embryonic development and tumor metastasis. Here we investigate the energetics of self-sustained mesoscale turbulence in confluent two-dimensional (2D) cell monolayers. We find that the kinetic energy and enstrophy of collective cell flows in both epithelial and non-epithelial cell monolayers collapse to a family of probability density functions, which follow the q-Gaussian distribution rather than the Maxwell–Boltzmann distribution. The enstrophy scales linearly with the kinetic energy as the monolayer matures. The energy spectra exhibit a power-decaying law at large wavenumbers, with a scaling exponent markedly different from that in the classical 2D Kolmogorov–Kraichnan turbulence. These energetic features are demonstrated to be common for all cell types on various substrates with a wide range of stiffness. This study provides unique clues to understand active natures of cell population and tissues.


2017 ◽  
Vol 284 (1863) ◽  
pp. 20171619 ◽  
Author(s):  
Richard C. Allen ◽  
Jan Engelstädter ◽  
Sebastian Bonhoeffer ◽  
Bruce A. McDonald ◽  
Alex R. Hall

Resistance spreads rapidly in pathogen or pest populations exposed to biocides, such as fungicides and antibiotics, and in many cases new biocides are in short supply. How can resistance be reversed in order to prolong the effectiveness of available treatments? Some key parameters affecting reversion of resistance are well known, such as the fitness cost of resistance. However, the population biological processes that actually cause resistance to persist or decline remain poorly characterized, and consequently our ability to manage reversion of resistance is limited. Where do susceptible genotypes that replace resistant lineages come from? What is the epidemiological scale of reversion? What information do we need to predict the mechanisms or likelihood of reversion? Here, we define some of the population biological processes that can drive reversion, using examples from a wide range of taxa and biocides. These processes differ primarily in the origin of revertant genotypes, but also in their sensitivity to factors such as coselection and compensatory evolution that can alter the rate of reversion, and the likelihood that resistance will re-emerge upon re-exposure to biocides. We therefore argue that discriminating among different types of reversion allows for better prediction of where resistance is most likely to persist.


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