scholarly journals The histone chaperoning pathway: from ribosome to nucleosome

2019 ◽  
Vol 63 (1) ◽  
pp. 29-43 ◽  
Author(s):  
Alonso J. Pardal ◽  
Filipe Fernandes-Duarte ◽  
Andrew J. Bowman
Keyword(s):  
Supply And Demand ◽  
Histone Chaperone ◽  
Histone Chaperones ◽  
Post Translational Modifications ◽  
Core Histones ◽  
Eukaryotic Dna ◽  
Chaperone Interactions ◽  
Almost All ◽  
Chromatin Biology ◽  
Cellular Components

AbstractNucleosomes represent the fundamental repeating unit of eukaryotic DNA, and comprise eight core histones around which DNA is wrapped in nearly two superhelical turns. Histones do not have the intrinsic ability to form nucleosomes; rather, they require an extensive repertoire of interacting proteins collectively known as ‘histone chaperones’. At a fundamental level, it is believed that histone chaperones guide the assembly of nucleosomes through preventing non-productive charge-based aggregates between the basic histones and acidic cellular components. At a broader level, histone chaperones influence almost all aspects of chromatin biology, regulating histone supply and demand, governing histone variant deposition, maintaining functional chromatin domains and being co-factors for histone post-translational modifications, to name a few. In this essay we review recent structural insights into histone-chaperone interactions, explore evidence for the existence of a histone chaperoning ‘pathway’ and reconcile how such histone-chaperone interactions may function thermodynamically to assemble nucleosomes and maintain chromatin homeostasis.

scholarly journals Histone transfer among chaperones

2012 ◽  
Vol 40 (2) ◽  
pp. 357-363 ◽  
Author(s):  
Wallace H. Liu ◽  
Mair E.A. Churchill
Keyword(s):  
Histone H3 ◽  
Histone Chaperone ◽  
Chromatin Assembly ◽  
Histone Chaperones ◽  
Nucleosome Assembly ◽  
Post Translational Modifications ◽  
Chromatin Dynamics ◽  
Nucleosomal Dna ◽  
Chaperone Interactions ◽  
Dependent Processes

The eukaryotic processes of nucleosome assembly and disassembly govern chromatin dynamics, in which histones exchange in a highly regulated manner to promote genome accessibility for all DNA-dependent processes. This regulation is partly carried out by histone chaperones, which serve multifaceted roles in co-ordinating the interactions of histone proteins with modification enzymes, nucleosome remodellers, other histone chaperones and nucleosomal DNA. The molecular details of the processes by which histone chaperones promote delivery of histones among their many functional partners are still largely undefined, but promise to offer insights into epigenome maintenance. In the present paper, we review recent findings on the histone chaperone interactions that guide the assembly of histones H3 and H4 into chromatin. This evidence supports the concepts of histone post-translational modifications and specific histone chaperone interactions as guiding principles for histone H3/H4 transactions during chromatin assembly.

scholarly journals Histone chaperones exhibit conserved functionality in nucleosome remodeling

2022 ◽  
Author(s):  
Pedro Buzon ◽  
Alejandro Velazquez-Cruz ◽  
Katiuska Gonzalez-Arzola ◽  
Antonio Diaz-Quintana ◽  
Irene Diaz-Moreno ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Single Molecule ◽  
Molecular Level ◽  
Eukaryotic Cell ◽  
Histone Chaperone ◽  
Histone Chaperones ◽  
Dynamic Nature ◽  
Nucleosome Remodeling ◽  
Molecular Action ◽  
Core Histones

Chromatin homeostasis mediates some of the most fundamental processes in the eukaryotic cell. In this regard, histone chaperones have emerged as major regulatory factors during DNA replication, repair, and transcription. However, the dynamic nature of these processes has severely impeded their characterization at the molecular level. Here we apply single-molecule probing by fluorescence optical tweezers to follow histone chaperone dynamics in real-time. The molecular action of SET/template-activating factor-Iβ and nucleophosmin 1, representing the two most common histone chaperone folds, were examined using both nucleosomes and isolated core histones. We show that these chaperones present binding specificity for partially dismantled nucleosomes and are able to recognize and disrupt non-native histone-DNA interactions. Furthermore, we reveal that cytochrome c inhibition of histone chaperones is coupled to chaperone accumulation on DNA-bound histones. Our single-molecule approach shows that despite the drastically different structures of these chaperones, they present conserved modes of action mediating nucleosome remodeling.

scholarly journals Functional analysis of chromatin assembly genes in tetrahymena thermophila

2021 ◽  
Author(s):  
Renu Jeyapala
Keyword(s):  
Functional Analysis ◽  
Tetrahymena Thermophila ◽  
Histone Variants ◽  
Chromatin Assembly ◽  
Base Pairs ◽  
Post Translational Modifications ◽  
Disease States ◽  
Core Histones ◽  
Chromatin Biology ◽  
Assembly Pathways

The basic structural unit of chromatin is the nucleosome composed of ~147 base pairs of DNA wrapped around an octamer of histone proteins. Post-translational modifications such as histone acetylation or the substitution of histone variants in place of core histones have been implicated in various chromatin related processes. There are two distinct chromatin assembly pathways. Replication-dependent mediated by CAF-1 (H3-H4) and replication-independent mediated by HIRA (H3.3-H4). Miss-regulation of chromatin assembly patterns result in the onset of many disease states such as cancer. Tetrahymena thermophila is a useful model for understanding basic questions in chromatin biology due to the segregation of transcriptionally active and silent chromatin into two distinct nuclei. To better characterize replication-dependent and independent chromatin assembly pathways in T. thermophila, I have engineered somatic knockouts (HIRA, CAC2, UBN1 and UBN2) and initiated the functional analysis of these chromatin assembly genes mediated in growth and development. The absence of CAC2 results in larger macronuclei and speculated to be a result of reduced histone H3-H4 deposition onto chromatin during growth.

scholarly journals Functional analysis of chromatin assembly genes in tetrahymena thermophila

2021 ◽  
Author(s):  
Renu Jeyapala
Keyword(s):  
Functional Analysis ◽  
Tetrahymena Thermophila ◽  
Histone Variants ◽  
Chromatin Assembly ◽  
Base Pairs ◽  
Post Translational Modifications ◽  
Disease States ◽  
Core Histones ◽  
Chromatin Biology ◽  
Assembly Pathways

The basic structural unit of chromatin is the nucleosome composed of ~147 base pairs of DNA wrapped around an octamer of histone proteins. Post-translational modifications such as histone acetylation or the substitution of histone variants in place of core histones have been implicated in various chromatin related processes. There are two distinct chromatin assembly pathways. Replication-dependent mediated by CAF-1 (H3-H4) and replication-independent mediated by HIRA (H3.3-H4). Miss-regulation of chromatin assembly patterns result in the onset of many disease states such as cancer. Tetrahymena thermophila is a useful model for understanding basic questions in chromatin biology due to the segregation of transcriptionally active and silent chromatin into two distinct nuclei. To better characterize replication-dependent and independent chromatin assembly pathways in T. thermophila, I have engineered somatic knockouts (HIRA, CAC2, UBN1 and UBN2) and initiated the functional analysis of these chromatin assembly genes mediated in growth and development. The absence of CAC2 results in larger macronuclei and speculated to be a result of reduced histone H3-H4 deposition onto chromatin during growth.

scholarly journals Human Histone Chaperone Nucleophosmin Enhances Acetylation-Dependent Chromatin Transcription

2005 ◽  
Vol 25 (17) ◽  
pp. 7534-7545 ◽  
Author(s):  
V. Swaminathan ◽  
A. Hari Kishore ◽  
K. K. Febitha ◽  
Tapas K. Kundu
Keyword(s):  
Transcriptional Activation ◽  
Histone Chaperone ◽  
Dependent Manner ◽  
Histone Chaperones ◽  
Cellular Processes ◽  
The Core ◽  
Core Histones ◽  
Nucleosomal Structure

ABSTRACT Histone chaperones are a group of proteins that aid in the dynamic chromatin organization during different cellular processes. Here, we report that the human histone chaperone nucleophosmin interacts with the core histones H3, H2B, and H4 but that this histone interaction is not sufficient to confer the chaperone activity. Significantly, nucleophosmin enhances the acetylation-dependent chromatin transcription and it becomes acetylated both in vitro and in vivo. Acetylation of nucleophosmin and the core histones was found to be essential for the enhancement of chromatin transcription. The acetylated NPM1 not only shows an increased affinity toward acetylated histones but also shows enhanced histone transfer ability. Presumably, nucleophosmin disrupts the nucleosomal structure in an acetylation-dependent manner, resulting in the transcriptional activation. These results establish nucleophosmin (NPM1) as a human histone chaperone that becomes acetylated, resulting in the enhancement of chromatin transcription.

scholarly journals Two factor authentication: Asf1 mediates crosstalk between H3 K14 and K56 acetylation

2019 ◽  
Vol 47 (14) ◽  
pp. 7380-7391 ◽  
Author(s):  
Joy M Cote ◽  
Yin-Ming Kuo ◽  
Ryan A Henry ◽  
Hataichanok Scherman ◽  
Daniel D Krzizike ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Repair ◽  
Histone Acetylation ◽  
Histone H3 ◽  
Histone Chaperone ◽  
Biochemical Data ◽  
Genome Replication ◽  
Histone Chaperones ◽  
Post Translational Modifications ◽  
Lysine Acetyltransferase

Abstract The ability of histone chaperone Anti-silencing factor 1 (Asf1) to direct acetylation of lysine 56 of histone H3 (H3K56ac) represents an important regulatory step in genome replication and DNA repair. In Saccharomyces cerevisiae, Asf1 interacts functionally with a second chaperone, Vps75, and the lysine acetyltransferase (KAT) Rtt109. Both Asf1 and Vps75 can increase the specificity of histone acetylation by Rtt109, but neither alter selectivity. However, changes in acetylation selectivity have been observed in histones extracted from cells, which contain a plethora of post-translational modifications. In the present study, we use a series of singly acetylated histones to test the hypothesis that histone pre-acetylation and histone chaperones function together to drive preferential acetylation of H3K56. We show that pre-acetylated H3K14ac/H4 functions with Asf1 to drive specific acetylation of H3K56 by Rtt109–Vps75. Additionally, we identified an exosite containing an acidic patch in Asf1 and show that mutations to this region alter Asf1-mediated crosstalk that changes Rtt109–Vps75 selectivity. Our proposed mechanism suggests that Gcn5 acetylates H3K14, recruiting remodeler complexes, allowing for the Asf1-H3K14ac/H4 complex to be acetylated at H3K56 by Rtt109–Vps75. This mechanism explains the conflicting biochemical data and the genetic links between Rtt109, Vps75, Gcn5 and Asf1 in the acetylation of H3K56.

scholarly journals Novel Roles for the Sirtuin Deacylase SIRT5 in Normal Physiology and in Cancer

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 741-741
Author(s):  
David Lombard
Keyword(s):  
Mitochondrial Matrix ◽  
Genomic Integrity ◽  
Biological Functions ◽  
Protein Targets ◽  
Post Translational Modifications ◽  
Catalytic Activities ◽  
Cellular Processes ◽  
Specific Cancer ◽  
Cancer Types ◽  
Chromatin Biology

Abstract Sirtuins are NAD+-dependent deacylases that regulate diverse cellular processes such as metabolic homeostasis and genomic integrity. Mammals possess seven sirtuin family members, SIRT1-SIRT7, that display diverse subcellular localization patterns, catalytic activities, protein targets, and biological functions. Three sirtuins, SIRT3, SIRT4, and SIRT5, are primarily located in the mitochondrial matrix. SIRT5 is a very inefficient deacetylase, instead removing negatively charged post-translational modifications (succinyl, glutaryl, and malonyl groups) from lysines of its target proteins, in mitochondria and throughout the cell. SIRT5 plays only modest known roles in normal physiology, with its major functions occurring in the heart under stress conditions. In contrast, in specific cancer types, including melanoma, we have identified a major pro-survival role for SIRT5. We have traced this function of SIRT5 to novel roles for this protein in regulating chromatin biology. New insights into mechanisms of SIRT5 action in cancer, and in normal myocardium, will be discussed.

scholarly journals The Profile of Post-translational Modifications of Histone H1 in Chromatin of Mouse Embryonic Stem Cells

Acta Naturae ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 82-91 ◽  
Author(s):  
T. Yu. Starkova ◽  
T. O. Artamonova ◽  
V. V. Ermakova ◽  
E. V. Chikhirzhina ◽  
M. A. Khodorkovskii ◽  
...  
Keyword(s):  
Stem Cells ◽  
Es Cells ◽  
Embryonic Stem ◽  
Histone H1 ◽  
Ion Cyclotron Resonance ◽  
Compact Structure ◽  
Post Translational Modifications ◽  
Differentiated Cells ◽  
Eukaryotic Dna ◽  
Nih 3T3

Linker histone H1 is one of the main chromatin proteins which plays an important role in organizing eukaryotic DNA into a compact structure. There is data indicating that cell type-specific post-translational modifications of H1 modulate chromatin activity. Here, we compared histone H1 variants from NIH/3T3, mouse embryonic fibroblasts (MEFs), and mouse embryonic stem (ES) cells using matrix-assisted laser desorption/ ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FT-ICR-MS). We found significant differences in the nature and positions of the post-translational modifications (PTMs) of H1.3-H1.5 variants in ES cells compared to differentiated cells. For instance, methylation of K75 in the H1.2-1.4 variants; methylation of K108, K148, K151, K152 K154, K155, K160, K161, K179, and K185 in H1.1, as well as of K168 in H1.2; phosphorylation of S129, T146, T149, S159, S163, and S180 in H1.1, T180 in H1.2, and T155 in H1.3 were identified exclusively in ES cells. The H1.0 and H1.2 variants in ES cells were characterized by an enhanced acetylation and overall reduced expression levels. Most of the acetylation sites of the H1.0 and H1.2 variants from ES cells were located within their C-terminal tails known to be involved in the stabilization of the condensed chromatin. These data may be used for further studies aimed at analyzing the functional role played by the revealed histone H1 PTMs in the self-renewal and differentiation of pluripotent stem cells.

Solution Structure of Histone Chaperone ANP32B: Interaction with Core Histones H3–H4 through Its Acidic Concave Domain

2010 ◽  
Vol 401 (1) ◽  
pp. 97-114 ◽  
Author(s):  
Naoya Tochio ◽  
Takashi Umehara ◽  
Yoshiko Munemasa ◽  
Toru Suzuki ◽  
Shin Sato ◽  
...  
Keyword(s):  
Solution Structure ◽  
Histone Chaperone ◽  
Core Histones

scholarly journals Comparative Genome-wide Analysis and Expression Profiling of Histone Acetyltransferase (HAT) Gene Family in Response to Hormonal Applications, Metal and Abiotic Stresses in Cotton

2019 ◽  
Vol 20 (21) ◽  
pp. 5311 ◽  
Author(s):  
Muhammad Imran ◽  
Sarfraz Shafiq ◽  
Muhammad Ansar Farooq ◽  
Muhammad Kashif Naeem ◽  
Emilie Widemann ◽  
...  
Keyword(s):  
Fiber Quality ◽  
Purifying Selection ◽  
Fiber Development ◽  
Amino Acid Sequences ◽  
Environmental Cues ◽  
Post Translational Modifications ◽  
Cellular Processes ◽  
Genome Wide ◽  
Selection Gene ◽  
Almost All

Post-translational modifications are involved in regulating diverse developmental processes. Histone acetyltransferases (HATs) play vital roles in the regulation of chromation structure and activate the gene transcription implicated in various cellular processes. However, HATs in cotton, as well as their regulation in response to developmental and environmental cues, remain unidentified. In this study, 9 HATs were identified from Gossypium raimondi and Gossypium arboretum, while 18 HATs were identified from Gossypium hirsutum. Based on their amino acid sequences, Gossypium HATs were divided into three groups: CPB, GNAT, and TAFII250. Almost all the HATs within each subgroup share similar gene structure and conserved motifs. Gossypium HATs are unevenly distributed on the chromosomes, and duplication analysis suggests that Gossypium HATs are under strong purifying selection. Gene expression analysis showed that Gossypium HATs were differentially expressed in various vegetative tissues and at different stages of fiber development. Furthermore, all the HATs were differentially regulated in response to various stresses (salt, drought, cold, heavy metal and DNA damage) and hormones (abscisic acid (ABA) and auxin (NAA)). Finally, co-localization of HAT genes with reported quantitative trait loci (QTL) of fiber development were reported. Altogether, these results highlight the functional diversification of HATs in cotton growth and fiber development, as well as in response to different environmental cues. This study enhances our understanding of function of histone acetylation in cotton growth, fiber development, and stress adaptation, which will eventually lead to the long-term improvement of stress tolerance and fiber quality in cotton.

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