scholarly journals Functional Diversity of Non-Histone Chromosomal Protein HmgB1

2020 ◽  
Vol 21 (21) ◽  
pp. 7948
Author(s):  
Elena Chikhirzhina ◽  
Tatyana Starkova ◽  
Anton Beljajev ◽  
Alexander Polyanichko ◽  
Alexey Tomilin

The functioning of DNA in the cell nucleus is ensured by a multitude of proteins, whose interactions with DNA as well as with other proteins lead to the formation of a complicated, organized, and quite dynamic system known as chromatin. This review is devoted to the description of properties and structure of the progenitors of the most abundant non-histone protein of the HMGB family—the HmgB1 protein. The proteins of the HMGB family are also known as “architectural factors” of chromatin, which play an important role in gene expression, transcription, DNA replication, and repair. However, as soon as HmgB1 goes outside the nucleus, it acquires completely different functions, post-translational modifications, and change of its redox state. Despite a lot of evidence of the functional activity of HmgB1, there are still many issues to be solved related to the mechanisms of the influence of HmgB1 on the development and treatment of different diseases—from oncological and cardiovascular diseases to pathologies during pregnancy and childbirth. Here, we describe molecular structure of the HmgB1 protein and discuss general mechanisms of its interactions with other proteins and DNA in cell.

2019 ◽  
Vol 15 (2) ◽  
pp. 120-130
Author(s):  
Mohammad Ghanbari ◽  
Reza Safaralizadeh ◽  
Kiyanoush Mohammadi

At the present time, cancer is one of the most lethal diseases worldwide. There are various factors involved in the development of cancer, including genetic factors, lifestyle, nutrition, and so on. Recent studies have shown that epigenetic factors have a critical role in the initiation and development of tumors. The histone post-translational modifications (PTMs) such as acetylation, methylation, phosphorylation, and other PTMs are important mechanisms that regulate the status of chromatin structure and this regulation leads to the control of gene expression. The histone acetylation is conducted by histone acetyltransferase enzymes (HATs), which are involved in transferring an acetyl group to conserved lysine amino acids of histones and consequently increase gene expression. On the basis of similarity in catalytic domains of HATs, these enzymes are divided into different groups such as families of GNAT, MYST, P300/CBP, SRC/P160, and so on. These enzymes have effective roles in apoptosis, signaling pathways, metastasis, cell cycle, DNA repair and other related mechanisms deregulated in cancer. Abnormal activation of HATs leads to uncontrolled amplification of cells and incidence of malignancy signs. This indicates that HAT might be an important target for effective cancer treatments, and hence there would be a need for further studies and designing of therapeutic drugs on this basis. In this study, we have reviewed the important roles of HATs in different human malignancies.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Guillermo Palou-Márquez ◽  
Isaac Subirana ◽  
Lara Nonell ◽  
Alba Fernández-Sanlés ◽  
Roberto Elosua

Abstract Background The integration of different layers of omics information is an opportunity to tackle the complexity of cardiovascular diseases (CVD) and to identify new predictive biomarkers and potential therapeutic targets. Our aim was to integrate DNA methylation and gene expression data in an effort to identify biomarkers related to cardiovascular disease risk in a community-based population. We accessed data from the Framingham Offspring Study, a cohort study with data on DNA methylation (Infinium HumanMethylation450 BeadChip; Illumina) and gene expression (Human Exon 1.0 ST Array; Affymetrix). Using the MOFA2 R package, we integrated these data to identify biomarkers related to the risk of presenting a cardiovascular event. Results Four independent latent factors (9, 19, 21—only in women—and 27), driven by DNA methylation, were associated with cardiovascular disease independently of classical risk factors and cell-type counts. In a sensitivity analysis, we also identified factor 21 as associated with CVD in women. Factors 9, 21 and 27 were also associated with coronary heart disease risk. Moreover, in a replication effort in an independent study three of the genes included in factor 27 were also present in a factor identified to be associated with myocardial infarction (CDC42BPB, MAN2A2 and RPTOR). Factor 9 was related to age and cell-type proportions; factor 19 was related to age and B cells count; factor 21 pointed to human immunodeficiency virus infection-related pathways and inflammation; and factor 27 was related to lifestyle factors such as alcohol consumption, smoking and body mass index. Inclusion of factor 21 (only in women) improved the discriminative and reclassification capacity of the Framingham classical risk function and factor 27 improved its discrimination. Conclusions Unsupervised multi-omics data integration methods have the potential to provide insights into the pathogenesis of cardiovascular diseases. We identified four independent factors (one only in women) pointing to inflammation, endothelium homeostasis, visceral fat, cardiac remodeling and lifestyles as key players in the determination of cardiovascular risk. Moreover, two of these factors improved the predictive capacity of a classical risk function.


Biomolecules ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Aishat Motolani ◽  
Matthew Martin ◽  
Mengyao Sun ◽  
Tao Lu

The nuclear factor kappa B (NF-κB) is a ubiquitous transcription factor central to inflammation and various malignant diseases in humans. The regulation of NF-κB can be influenced by a myriad of post-translational modifications (PTMs), including phosphorylation, one of the most popular PTM formats in NF-κB signaling. The regulation by phosphorylation modification is not limited to NF-κB subunits, but it also encompasses the diverse regulators of NF-κB signaling. The differential site-specific phosphorylation of NF-κB itself or some NF-κB regulators can result in dysregulated NF-κB signaling, often culminating in events that induce cancer progression and other hyper NF-κB related diseases, such as inflammation, cardiovascular diseases, diabetes, as well as neurodegenerative diseases, etc. In this review, we discuss the regulatory role of phosphorylation in NF-κB signaling and the mechanisms through which they aid cancer progression. Additionally, we highlight some of the known and novel NF-κB regulators that are frequently subjected to phosphorylation. Finally, we provide some future perspectives in terms of drug development to target kinases that regulate NF-κB signaling for cancer therapeutic purposes.


1979 ◽  
Vol 183 (3) ◽  
pp. 657-662 ◽  
Author(s):  
P D Cary ◽  
K V Shooter ◽  
G H Goodwin ◽  
E W Johns ◽  
J Y Olayemi ◽  
...  

The interaction of the non-histone chromosomal protein HMG (high-mobility group) 1 with histone H1 subfractions was investigated by equilibrium sedimentation and n.m.r. sectroscopy. In contrast with a previous report [Smerdon & Isenberg (1976) Biochemistry 15, 4242–4247], it was found, by using equilibrium-sedimentation analysis, that protein HMG 1 binds to all three histone H1 subfractions CTL1, CTL2, and CTL3, arguing against there being a specific interaction between protein HMG 1 and only two of the subfractions, CTL1 and CTL2. Raising the ionic strength of the solutions prevents binding of protein HMG 1 to total histone H1 and the three subfractions, suggesting that the binding in vitro is simply a non-specific ionic interaction between acidic regions of the non-histone protein and the basic regions of the histone. Protein HMG 1 binds to histone H5 also, supporting this view. The above conclusions are supported by n.m.r. studies of protein HMG 1/histone H1 subfraction mixtures. When the two proteins were mixed, there was little perturbation of the n.m.r. spectra and there was no evidence for specific interaction of protein HMG 1 with any of the subfractions. It therefore remains an open question as to whether protein HMG 1 and histone H1 are complexed together in chromatin.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Makiko Oboshi ◽  
Yoshiro Naito ◽  
Hisashi Sawada ◽  
Toshihiro Iwasaku ◽  
Yoshitaka Okuhara ◽  
...  

Introduction: Deep vein thrombosis (DVT) is a major cause of pulmonary thromboembolism. On the other hand, iron is an essential element for maintaining physiological homeostasis in the body, whereas excess iron leads to toxicity and free radical damage. Hence, iron accumulation is associated with the pathogenesis of several cardiovascular diseases. We have previously reported that dietary iron restriction (IR) prevents the development of hypertension and chronic kidney disease (CKD) in animal models of several cardiovascular diseases. In addition, we have shown that intracellular iron transport protein, transferrin receptor 1 (TfR1), is involved in the mechanism of several cardiovascular diseases. In this study, we hypothesized that iron and TfR1 play roles in the pathogenesis of DVT. We investigate the effects of dietary IR on the thrombus formation and resolution in a rat model of DVT. Methods: We performed the ligation of inferior vena cava to induce DVT in 8-week-old male Sprague-Dawley rats. After the ligation, rats were given either a normal diet (DVT group) or iron-restricted diet (DVT+IR group). The thrombus was harvested at 5days after the ligation. Results: At first, TfR1 expression was increased in the thrombus of a rat model of DVT, suggesting that iron and TfR1 play roles in the pathogenesis of DVT. Interestingly, dietary iron restriction reduced the thrombus size compared with the DVT group (180±17 mg/cm vs 135±13 mg/cm, DVT vs DVT+IR ; p < 0.05). Intrathrombotic collagen content was diminished in the DVT+IR group compared with the DVT group. Intrathrombotic gene expression and activity of matrix metalloproteinase (MMP)-9 were increased in the DVT+IR group compared with the DVT group. In addition, the numbers of CD68 positive cells in the thrombus were fewer in the DVT+IR group than in the DVT group. Furthermore, intrathrombotic gene expression of urokinase-type plasminogen activator and tissue-type plasminogen activator was higher in the DVT+IR group than in the DVT group. Conclusions: These results suggest that iron plays a role in the pathogenesis of DVT.


Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 416 ◽  
Author(s):  
Dea Slade

DNA replication and repair are essential cellular processes that ensure genome duplication and safeguard the genome from deleterious mutations. Both processes utilize an abundance of enzymatic functions that need to be tightly regulated to ensure dynamic exchange of DNA replication and repair factors. Proliferating cell nuclear antigen (PCNA) is the major coordinator of faithful and processive replication and DNA repair at replication forks. Post-translational modifications of PCNA, ubiquitination and acetylation in particular, regulate the dynamics of PCNA-protein interactions. Proliferating cell nuclear antigen (PCNA) monoubiquitination elicits ‘polymerase switching’, whereby stalled replicative polymerase is replaced with a specialized polymerase, while PCNA acetylation may reduce the processivity of replicative polymerases to promote homologous recombination-dependent repair. While regulatory functions of PCNA ubiquitination and acetylation have been well established, the regulation of PCNA-binding proteins remains underexplored. Considering the vast number of PCNA-binding proteins, many of which have similar PCNA binding affinities, the question arises as to the regulation of the strength and sequence of their binding to PCNA. Here I provide an overview of post-translational modifications on both PCNA and PCNA-interacting proteins and discuss their relevance for the regulation of the dynamic processes of DNA replication and repair.


Author(s):  
Suresh Kumar

Genome-wide epigenetic changes in plants are being reported during the development and environmental stresses, which are often correlated with gene expression at the transcriptional level. Sum total of the biochemical changes in nuclear DNA, post-translational modifications in histone proteins and variations in the biogenesis of non-coding RNAs in a cell is known as epigenome. These changes are often responsible for variation in expression of the gene without any change in the underlying nucleotide sequence. The changes might also cause variation in chromatin structure resulting into the changes in function/activity of the genome. The epigenomic changes are dynamic with respect to the endogenous and/or environmental stimuli which affect phenotypic plasticity of the organism. Both, the epigenetic changes and variation in gene expression might return to the pre-stress state soon after withdrawal of the stress. However, a part of the epigenetic changes may be retained which is reported to play role in acclimatization, adaptation as well as in the evolutionary processes. Understanding epigenome-engineering for improved stress tolerance in plants has become essential for better utilization of the genetic factors. This review delineates the importance of epigenomics towards possible improvement of plant&rsquo;s responses to environmental stresses for climate resilient agriculture.


2018 ◽  
Vol 20 (1) ◽  
pp. 102 ◽  
Author(s):  
Justine Habibian ◽  
Bradley Ferguson

Approximately five million United States (U.S.) adults are diagnosed with heart failure (HF), with eight million U.S. adults projected to suffer from HF by 2030. With five-year mortality rates following HF diagnosis approximating 50%, novel therapeutic treatments are needed for HF patients. Pre-clinical animal models of HF have highlighted histone deacetylase (HDAC) inhibitors as efficacious therapeutics that can stop and potentially reverse cardiac remodeling and dysfunction linked with HF development. HDACs remove acetyl groups from nucleosomal histones, altering DNA-histone protein electrostatic interactions in the regulation of gene expression. However, HDACs also remove acetyl groups from non-histone proteins in various tissues. Changes in histone and non-histone protein acetylation plays a key role in protein structure and function that can alter other post translational modifications (PTMs), including protein phosphorylation. Protein phosphorylation is a well described PTM that is important for cardiac signal transduction, protein activity and gene expression, yet the functional role for acetylation-phosphorylation cross-talk in the myocardium remains less clear. This review will focus on the regulation and function for acetylation-phosphorylation cross-talk in the heart, with a focus on the role for HDACs and HDAC inhibitors as regulators of acetyl-phosphorylation cross-talk in the control of cardiac function.


2020 ◽  
Vol 21 (3) ◽  
pp. 751 ◽  
Author(s):  
Karolina Łuczkowska ◽  
Dorota Rogińska ◽  
Zofia Ulańczyk ◽  
Bogusław Machaliński

Peripheral neuropathy is one of the main side-effects of novel therapeutics used in oncohematological diseases, but the molecular basis underlying its development and progression as well as neurotoxicity mechanisms induced by the use of these therapeutics are still not fully elucidated. The aim of this study was to demonstrate the effect of bortezomib on global gene and miRNA expression on PC12-derived nerve cells. Microarray analysis showed that expression of 1383 genes was downregulated at least two fold and 671 genes were upregulated at least two fold in PC12-derived nerve cells treated with bortezomib compared to untreated/control cells. Analysis of functional annotations mainly identified downregulated processes (e.g., regulation of cell cycle, DNA replication and repair, regulation of cell migration, neuron projection morphogenesis and neurotransmitter secretion). The result of miRNA expression analysis demonstrated only 11 significantly downregulated miRNAs (at least two fold) in bortezomib-treated PC12-derived nerve cells vs. control cells. MiRNAs regulate gene expression, therefore we decided to conduct an analysis comparing the outcomes of miRNA microarray expression data to the obtained mRNA data. The most interesting miRNA–target gene correlation is downregulated expression of miR-130a-3p and miR-152-3p and as a result of this downregulation the expression of the Gadd45 increased. This gene is a member of a group of genes, the transcript expression of which is enhanced after stressful growth arrest conditions and treatment with DNA-damaging agents like drugs or mutagens.


Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 570 ◽  
Author(s):  
Amaia González-Magaña ◽  
Francisco J. Blanco

Proliferating cell nuclear antigen (PCNA) is an essential factor in DNA replication and repair. It forms a homotrimeric ring that embraces the DNA and slides along it, anchoring DNA polymerases and other DNA editing enzymes. It also interacts with regulatory proteins through a sequence motif known as PCNA Interacting Protein box (PIP-box). We here review the latest contributions to knowledge regarding the structure-function relationships in human PCNA, particularly the mechanism of sliding, and of the molecular recognition of canonical and non-canonical PIP motifs. The unique binding mode of the oncogene p15 is described in detail, and the implications of the recently discovered structure of PCNA bound to polymerase δ are discussed. The study of the post-translational modifications of PCNA and its partners may yield therapeutic opportunities in cancer treatment, in addition to illuminating the way PCNA coordinates the dynamic exchange of its many partners in DNA replication and repair.


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