Role of glycosylation in nucleating protein folding and stability

2017 ◽  
Vol 474 (14) ◽  
pp. 2333-2347 ◽  
Author(s):  
Nisha Grandhi Jayaprakash ◽  
Avadhesha Surolia

Glycosylation constitutes one of the most common, ubiquitous and complex forms of post-translational modification. It commences with the synthesis of the protein and plays a significant role in deciding its folded state, oligomerization and thus its function. Recent studies have demonstrated that N-linked glycans help proteins to fold as the stability and folding kinetics are altered with the removal of the glycans from them. Several studies have shown that it alters not only the thermodynamic stability but also the structural features of the folded proteins modulating their interactions and functions. Their inhibition and perturbations have been implicated in diseases from diabetes to degenerative disorders. The intent of this review is to provide insight into the recent advancements in the general understanding on the aspect of glycosylation driven stability of proteins that is imperative to their function and finally their role in health and disease states.

2017 ◽  
Author(s):  
Sean M. Kearney ◽  
Sean M. Gibbons ◽  
Mathilde Poyet ◽  
Thomas Gurry ◽  
Kevin Bullock ◽  
...  

AbstractEndospore-formers in the human microbiota are well adapted for host-to-host transmission, and an emerging consensus points to their role in determining health and disease states in the gut. The human gut, more than any other environment, encourages the maintenance of endospore formation, with recent culture-based work suggesting that over 50% of genera in the microbiome carry genes attributed to this trait. However, there has been limited work on the ecological role of endospores and other stress-resistant cellular states in the human gut. In fact, there is no data to indicate whether organisms with the genetic potential to form endospores actually form endosporesin situand how sporulation varies across individuals and over time. Here, we applied a culture-independent protocol to enrich for endospores and other stress-resistant cells in human feces to identify variation in these states across people and within an individual over time. We see that cells with resistant states are more likely than those without to be shared among multiple individuals, which suggests that these resistant states are particularly adapted for cross-host dissemination. Furthermore, we use untargeted fecal metabolomics in 24 individuals and within a person over time to show that these organisms respond to shared environmental signals, and in particular, dietary fatty acids, that likely mediate colonization of recently disturbed human guts.


2018 ◽  
Vol 43 (11) ◽  
pp. 1122-1130 ◽  
Author(s):  
Baraa K. Al-Khazraji ◽  
J. Kevin Shoemaker

The autonomic nervous system elicits continuous beat-by-beat homeostatic adjustments to cardiovascular control. These modifications are mediated by sensory inputs (e.g., baroreceptors, metaboreceptors, pulmonary, thermoreceptors, and chemoreceptors afferents), integration at the brainstem control centres (i.e., medulla), and efferent autonomic neural outputs (e.g., spinal, preganglionic, and postganglionic pathways). However, extensive electrical stimulation and functional imaging research show that the brain’s higher cortical regions (e.g., insular cortex, medial prefrontal cortex, anterior cingulate cortex) partake in homeostatic regulation of the cardiovascular system at rest and during exercise. We now appreciate that these cortical areas form a network, namely the “cortical autonomic network” (CAN), which operate as part of a larger central autonomic network comprising 2-way communication of cortical and subcortical areas to exert autonomic influence. Interestingly, differential patterns of CAN activity and ensuing cardiovascular control are present in disease states, thereby highlighting the importance of considering the role of CAN as an integral aspect of cardiovascular regulation in health and disease. This review discusses current knowledge on human cortical autonomic activation during volitional exercise, and the role of exercise training on this activation in both health and disease.


2021 ◽  
Author(s):  
Saeed Shoaie ◽  
Sunjae Lee ◽  
Mathieu Almeida ◽  
Gholamreza Bidkhori ◽  
Nicolas Pons ◽  
...  

Abstract The role of gut microbiota in humans is of great interest, and metagenomics provided the possibilities for extensively analysing bacterial diversity in health and disease. Here we explored the human gut microbiome samples across 19 countries, performing compositional, functional and integrative analysis. To complement these data and analyse the stability of the microbiome, we followed 86 healthy Swedish individuals over one year, with four sampling times and extensive clinical phenotyping. The integrative analysis of temporal microbiome changes shows the existence of two types of species with a tendency to vary in abundance with time, here called outflow and inflow species. Importantly, the former tends to be enriched in disease, while the latter is enriched in health. We suggest that the decrease of disease-associated outflow and the increase of health-associated inflow species with time may be a fundamental albeit previously unrecognized aspect of the homeostasis maintenance in a healthy microbiome.


2014 ◽  
Vol 27 (1) ◽  
pp. 94-106 ◽  
Author(s):  
Emma L. Beckett ◽  
Zoe Yates ◽  
Martin Veysey ◽  
Konsta Duesing ◽  
Mark Lucock

A growing number of studies in recent years have highlighted the importance of molecular nutrition as a potential determinant of health and disease. In particular, the ability of micronutrients to regulate the final expression of gene products via modulation of transcription and translation is now being recognised. Modulation of microRNA (miRNA) by nutrients is one pathway by which nutrition may mediate gene expression. miRNA, a class of non-coding RNA, can directly regulate gene expression post-transcriptionally. In addition, miRNA are able to indirectly influence gene expression potential at the transcriptional level via modulation of the function of components of the epigenetic machinery (DNA methylation and histone modifications). These mechanisms interact to form a complex, bi-directional regulatory circuit modulating gene expression. Disease-specific miRNA profiles have been identified in multiple disease states, including those with known dietary risk factors. Therefore, the role that nutritional components, in particular, vitamins and minerals, play in the modulation of miRNA profiles, and consequently health and disease, is increasingly being investigated, and as such is a timely subject for review. The recently posited potential for viable exogenous miRNA to enter human blood circulation from food sources adds another interesting dimension to the potential for dietary miRNA to contribute to gene modulation.


2017 ◽  
Vol 22 (7) ◽  
pp. 787-800 ◽  
Author(s):  
Dimitrios Doultsinos ◽  
Tony Avril ◽  
Stéphanie Lhomond ◽  
Nicolas Dejeans ◽  
Philippe Guédat ◽  
...  

The unfolded protein response (UPR) is an integrated, adaptive biochemical process that is inextricably linked with cell homeostasis and paramount to maintenance of normal physiological function. Prolonged accumulation of improperly folded proteins in the endoplasmic reticulum (ER) leads to stress. This is the driving stimulus behind the UPR. As such, prolonged ER stress can push the UPR past beneficial functions such as reduced protein production and increased folding and clearance to apoptotic signaling. The UPR is thus contributory to the commencement, maintenance, and exacerbation of a multitude of disease states, making it an attractive global target to tackle conditions sorely in need of novel therapeutic intervention. The accumulation of information of screening tools, readily available therapies, and potential pathways to drug development is the cornerstone of informed clinical research and clinical trial design. Here, we review the UPR’s involvement in health and disease and, beyond providing an in-depth description of the molecules found to target the three UPR arms, we compile all the tools available to screen for and develop novel therapeutic agents that modulate the UPR with the scope of future disease intervention.


Author(s):  
Lauren Eades ◽  
Michael Drozd ◽  
Richard M. Cubbon

Innate immune function is shaped by prior exposures in a phenomenon often referred to as ‘memory’ or ‘training’. Diverse stimuli, ranging from pathogen-associated molecules to atherogenic lipoproteins, induce long-lasting training, impacting on future responses, even to distinct stimuli. It is now recognised that epigenetic modifications in innate immune cells, and their progenitors, underpin these sustained behavioural changes, and that rewired cellular metabolism plays a key role in facilitating such epigenetic marks. Oxygen is central to cellular metabolism, and cells exposed to hypoxia undergo profound metabolic rewiring. A central effector of these responses are the hypoxia inducible factors (or HIFs), which drive transcriptional programmes aiming to adapt cellular homeostasis, such as by increasing glycolysis. These metabolic shifts indirectly promote post-translational modification of the DNA-binding histone proteins, and also of DNA itself, which are retained even after cellular oxygen tension and metabolism normalise, chronically altering DNA accessibility and utilisation. Notably, the activity of HIFs can be induced in some normoxic circumstances, indicating their broad importance to cell biology, irrespective of oxygen tension. Some HIFs are implicated in innate immune training and hypoxia is present in many disease states, yet many questions remain about the association between hypoxia and training, both in health and disease. Moreover, it is now appreciated that cellular responses to hypoxia are mediated by non-HIF pathways, suggesting that other mechanisms of training may be possible. This review sets out to define what is already known about the topic, address gaps in our knowledge, and provide recommendations for future research.


2021 ◽  
Vol 22 (9) ◽  
pp. 4733
Author(s):  
Jin-Sun Hwang ◽  
Young-Joo Shin

Choline is essential for maintaining the structure and function of cells in humans. Choline plays an important role in eye health and disease. It is a precursor of acetylcholine, a neurotransmitter of the parasympathetic nervous system, and it is involved in the production and secretion of tears by the lacrimal glands. It also contributes to the stability of the cells and tears on the ocular surface and is involved in retinal development and differentiation. Choline deficiency is associated with retinal hemorrhage, glaucoma, and dry eye syndrome. Choline supplementation may be effective for treating these diseases.


2016 ◽  
Vol 113 (33) ◽  
pp. E4801-E4809 ◽  
Author(s):  
Kendrick H. Yim ◽  
Thomas L. Prince ◽  
Shiwei Qu ◽  
Fang Bai ◽  
Patricia A. Jennings ◽  
...  

Because of their importance in maintaining protein homeostasis, molecular chaperones, including heat-shock protein 90 (Hsp90), represent attractive drug targets. Although a number of Hsp90 inhibitors are in preclinical/clinical development, none strongly differentiate between constitutively expressed Hsp90β and stress-induced Hsp90α, the two cytosolic paralogs of this molecular chaperone. Thus, the importance of inhibiting one or the other paralog in different disease states remains unknown. We show that the natural product, gambogic acid (GBA), binds selectively to a site in the middle domain of Hsp90β, identifying GBA as an Hsp90β-specific Hsp90 inhibitor. Furthermore, using computational and medicinal chemistry, we identified a GBA analog, referred to as DAP-19, which binds potently and selectively to Hsp90β. Because of its unprecedented selectivity for Hsp90β among all Hsp90 paralogs, GBA thus provides a new chemical tool to study the unique biological role of this abundantly expressed molecular chaperone in health and disease.


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