scholarly journals Yeast histone H3 and H4 amino termini are important for nucleosome assembly in vivo and in vitro: redundant and position-independent functions in assembly but not in gene regulation.

1996 ◽  
Vol 10 (6) ◽  
pp. 686-699 ◽  
Author(s):  
X Ling ◽  
T A Harkness ◽  
M C Schultz ◽  
G Fisher-Adams ◽  
M Grunstein
Keyword(s):  
Gene Regulation ◽  
Histone H3 ◽  
Nucleosome Assembly ◽  
Independent Functions

scholarly journals In Vivo Study of the Nucleosome Assembly Functions of ASF1 Histone Chaperones in Human Cells

2008 ◽  
Vol 28 (11) ◽  
pp. 3672-3685 ◽  
Author(s):  
Angélique Galvani ◽  
Régis Courbeyrette ◽  
Morgane Agez ◽  
Françoise Ochsenbein ◽  
Carl Mann ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Histone H3 ◽  
Direct Determination ◽  
Human Cells ◽  
Chromatin Assembly ◽  
Histone Chaperones ◽  
Nucleosome Assembly ◽  
Assembly Factor

ABSTRACT Histone chaperones have been implicated in nucleosome assembly and disassembly as well as histone modification. ASF1 is a highly conserved histone H3/H4 chaperone that synergizes in vitro with two other histone chaperones, chromatin assembly factor 1 (CAF-1) and histone repression A factor (HIRA), in DNA synthesis-coupled and DNA synthesis-independent nucleosome assembly. Here, we identify mutants of histones H3.1 and H3.3 that are unable to interact with human ASF1A and ASF1B isoforms but that are still competent to bind CAF-1 and HIRA, respectively. We show that these mutant histones are inefficiently deposited into chromatin in vivo. Furthermore, we found that both ASF1A and ASF1B participate in the DNA synthesis-independent deposition of H3.3 in HeLa cells, thus highlighting an unexpected role for ASF1B in this pathway. This pathway does not require interaction of ASF1 with HIRA. We provide the first direct determination that ASF1A and ASF1B play a role in the efficiency of nucleosome assembly in vivo in human cells.

Differential use of SCL/TAL-1 DNA-binding domain in developmental hematopoiesis

Blood ◽  
2008 ◽  
Vol 112 (4) ◽  
pp. 1056-1067 ◽  
Author(s):  
Mira T. Kassouf ◽  
Hedia Chagraoui ◽  
Paresh Vyas ◽  
Catherine Porcher
Keyword(s):  
Dna Binding ◽  
Molecular Mechanisms ◽  
Binding Activity ◽  
Hematopoietic Stem ◽  
Helix Loop Helix ◽  
Experimental Systems ◽  
Dna Binding Activity ◽  
Independent Functions

Abstract Dissecting the molecular mechanisms used by developmental regulators is essential to understand tissue specification/differentiation. SCL/TAL-1 is a basic helix-loop-helix transcription factor absolutely critical for hematopoietic stem/progenitor cell specification and lineage maturation. Using in vitro and forced expression experimental systems, we previously suggested that SCL might have DNA-binding–independent functions. Here, to assess the requirements for SCL DNA-binding activity in vivo, we examined hematopoietic development in mice carrying a germline DNA-binding mutation. Remarkably, in contrast to complete absence of hematopoiesis and early lethality in scl-null embryos, specification of hematopoietic cells occurred in homozygous mutant embryos, indicating that direct DNA binding is dispensable for this process. Lethality was forestalled to later in development, although some mice survived to adulthood. Anemia was documented throughout development and in adulthood. Cellular and molecular studies showed requirements for SCL direct DNA binding in red cell maturation and indicated that scl expression is positively autoregulated in terminally differentiating erythroid cells. Thus, different mechanisms of SCL's action predominate depending on the developmental/cellular context: indirect DNA binding activities and/or sequestration of other nuclear regulators are sufficient in specification processes, whereas direct DNA binding functions with transcriptional autoregulation are critically required in terminal maturation processes.

α2-Adrenoceptor agonist dexmedetomidine protects septic acute kidney injury through increasing BMP-7 and inhibiting HDAC2 and HDAC5

2012 ◽  
Vol 303 (10) ◽  
pp. F1443-F1453 ◽  
Author(s):  
Chung-Hsi Hsing ◽  
Chiou-Feng Lin ◽  
Edmund So ◽  
Ding-Ping Sun ◽  
Tai-Chi Chen ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Histone Deacetylases ◽  
Trichostatin A ◽  
Histone H3 ◽  
Cecal Ligation ◽  
Kidney Injury ◽  
Protective Effects ◽  
Tnf Α

Bone morphogenetic protein (BMP)-7 protects sepsis-induced acute kidney injury (AKI). Dexmedetomidine (DEX), an α2-adrenoceptor (α2-AR) agonist, has anti-inflammatory effects. We investigated the protective effects of DEX on sepsis-induced AKI and the expression of BMP-7 and histone deacetylases (HDACs). In vitro , the effects of DEX or trichostatin A (TSA, an HDAC inhibitor) on TNF-α, monocyte chemotactic protein (MCP-1), BMP-7, and HDAC mRNA expression in LPS-stimulated rat renal tubular epithelial NRK52E cells, was determined using real-time PCR. In vivo, mice were intraperitoneally injected with DEX (25 μg/kg) or saline immediately and 12 h after cecal ligation and puncture (CLP) surgery. Twenty-four hours after CLP, we examined kidney injury and renal TNF-α, MCP-1, BMP-7, and HDAC expression. Survival was monitored for 120 h. LPS increased HDAC2, HDAC5, TNF-α, and MCP-1 expression, but decreased BMP-7 expression in NRK52E cells. DEX treatment decreased the HDAC2, HDAC5, TNF-α, and MCP-1 expression, but increased BMP-7 and acetyl histone H3 expression, whose effects were blocked by yohimbine, an α2-AR antagonist. With DEX treatment, the LPS-induced TNF-α expression and cell death were attenuated in scRNAi-NRK52E but not BMP-7 RNAi-NRK52E cells. In CLP mice, DEX treatment increased survival and attenuated AKI. The expression of HDAC2, HDAC5, TNF-α, and MCP-1 mRNA in the kidneys of CLP mice was increased, but BMP-7 was decreased. However, DEX treatment reduced those changes. DEX reduces sepsis-induced AKI by decreasing TNF-α and MCP-1 and increasing BMP-7, which is associated with decreasing HDAC2 and HDAC5, as well as increasing acetyl histone H3.

scholarly journals The chromatin-binding protein HMGN3 stimulates histone acetylation and transcription across the Glyt1 gene

2012 ◽  
Vol 442 (3) ◽  
pp. 495-505 ◽  
Author(s):  
Gráinne Barkess ◽  
Yuri Postnikov ◽  
Chrisanne D. Campos ◽  
Shivam Mishra ◽  
Gokula Mohan ◽  
...  
Keyword(s):  
Histone Modifications ◽  
Splice Variants ◽  
Binding Protein ◽  
Histone H3 ◽  
Camp Response Element Binding ◽  
Element Binding Protein ◽  
H3k14 Acetylation ◽  
H3 Acetylation

HMGNs are nucleosome-binding proteins that alter the pattern of histone modifications and modulate the binding of linker histones to chromatin. The HMGN3 family member exists as two splice forms, HMGN3a which is full-length and HMGN3b which lacks the C-terminal RD (regulatory domain). In the present study, we have used the Glyt1 (glycine transporter 1) gene as a model system to investigate where HMGN proteins are bound across the locus in vivo, and to study how the two HMGN3 splice variants affect histone modifications and gene expression. We demonstrate that HMGN1, HMGN2, HMGN3a and HMGN3b are bound across the Glyt1 gene locus and surrounding regions, and are not enriched more highly at the promoter or putative enhancer. We conclude that the peaks of H3K4me3 (trimethylated Lys4 of histone H3) and H3K9ac (acetylated Lys9 of histone H3) at the active Glyt1a promoter do not play a major role in recruiting HMGN proteins. HMGN3a/b binding leads to increased H3K14 (Lys14 of histone H3) acetylation and stimulates Glyt1a expression, but does not alter the levels of H3K4me3 or H3K9ac enrichment. Acetylation assays show that HMGN3a stimulates the ability of PCAF [p300/CREB (cAMP-response-element-binding protein)-binding protein-associated factor] to acetylate nucleosomal H3 in vitro, whereas HMGN3b does not. We propose a model where HMGN3a/b-stimulated H3K14 acetylation across the bodies of large genes such as Glyt1 can lead to more efficient transcription elongation and increased mRNA production.

scholarly journals Essential Role of Chromatin Assembly Factor-1–mediated Rapid Nucleosome Assembly for DNA Replication and Cell Division in Vertebrate Cells

2007 ◽  
Vol 18 (1) ◽  
pp. 129-141 ◽  
Author(s):  
Yasunari Takami ◽  
Tatsuya Ono ◽  
Tatsuo Fukagawa ◽  
Kei-ichi Shibahara ◽  
Tatsuo Nakayama
Keyword(s):  
Dna Replication ◽  
Essential Role ◽  
Chromatin Assembly ◽  
Nuclear Antigen ◽  
Nucleosome Assembly ◽  
Chromatin Assembly Factor ◽  
Assembly Factor

Chromatin assembly factor-1 (CAF-1), a complex consisting of p150, p60, and p48 subunits, is highly conserved from yeast to humans and facilitates nucleosome assembly of newly replicated DNA in vitro. To investigate roles of CAF-1 in vertebrates, we generated two conditional DT40 mutants, respectively, devoid of CAF-1p150 and p60. Depletion of each of these CAF-1 subunits led to delayed S-phase progression concomitant with slow DNA synthesis, followed by accumulation in late S/G2 phase and aberrant mitosis associated with extra centrosomes, and then the final consequence was cell death. We demonstrated that CAF-1 is necessary for rapid nucleosome formation during DNA replication in vivo as well as in vitro. Loss of CAF-1 was not associated with the apparent induction of phosphorylations of S-checkpoint kinases Chk1 and Chk2. To elucidate the precise role of domain(s) in CAF-1p150, functional dissection analyses including rescue assays were preformed. Results showed that the binding abilities of CAF-1p150 with CAF-1p60 and DNA polymerase sliding clamp proliferating cell nuclear antigen (PCNA) but not with heterochromatin protein HP1-γ are required for cell viability. These observations highlighted the essential role of CAF-1–dependent nucleosome assembly in DNA replication and cell proliferation through its interaction with PCNA.

scholarly journals Regulation of the Dot1 histone H3K79 methyltransferase by histone H4K16 acetylation

Science ◽  
2021 ◽  
Vol 371 (6527) ◽  
pp. eabc6663
Author(s):  
Marco Igor Valencia-Sánchez ◽  
Pablo De Ioannes ◽  
Miao Wang ◽  
David M. Truong ◽  
Rachel Lee ◽  
...  
Keyword(s):  
Histone H3 ◽  
Histone H4 ◽  
Histone H2b ◽  
Epigenetic State ◽  
Optimal Maintenance ◽  
H4k16 Acetylation ◽  
H3k79 Methylation ◽  
Regulate Gene

Dot1 (disruptor of telomeric silencing-1), the histone H3 lysine 79 (H3K79) methyltransferase, is conserved throughout evolution, and its deregulation is found in human leukemias. Here, we provide evidence that acetylation of histone H4 allosterically stimulates yeast Dot1 in a manner distinct from but coordinating with histone H2B ubiquitination (H2BUb). We further demonstrate that this stimulatory effect is specific to acetylation of lysine 16 (H4K16ac), a modification central to chromatin structure. We provide a mechanism of this histone cross-talk and show that H4K16ac and H2BUb play crucial roles in H3K79 di- and trimethylation in vitro and in vivo. These data reveal mechanisms that control H3K79 methylation and demonstrate how H4K16ac, H3K79me, and H2BUb function together to regulate gene transcription and gene silencing to ensure optimal maintenance and propagation of an epigenetic state.

Effects of histone acetylation on chromatin topology in vivo

1992 ◽  
Vol 12 (11) ◽  
pp. 5004-5014
Author(s):  
L C Lutter ◽  
L Judis ◽  
R F Paretti
Keyword(s):  
Transcriptional Activation ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Nucleosome Assembly ◽  
Linking Number ◽  
Histone Hyperacetylation ◽  
Proposed Model ◽  
Butyrate Treatment

Recently a model for eukaryotic transcriptional activation has been proposed in which histone hyperacetylation causes release of nucleosomal supercoils, and this unconstrained tension in turn stimulates transcription (V. G. Norton, B. S. Imai, P. Yau, and E. M. Bradbury, Cell 57:449-457, 1989; V. G. Norton, K. W. Marvin, P. Yau, and E. M. Bradbury, J. Biol. Chem. 265:19848-19852, 1990). These studies analyzed the effect of histone hyperacetylation on the change in topological linking number which occurs during nucleosome assembly in vitro. We have tested this model by determining the effect of histone hyperacetylation on the linking number change which occurs during assembly in vivo. We find that butyrate treatment of cells infected with simian virus 40 results in hyperacetylation of the histones of the extracted viral minichromosome as expected. However, the change in constrained supercoils of the minichromosome DNA is minimal, a result which is inconsistent with the proposed model. These results indicate that the proposed mechanism of transcriptional activation is unlikely to take place in the cell.

scholarly journals The Co-Chaperone HspBP1 Is a Novel Component of Stress Granules that Regulates Their Formation

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 825
Author(s):  
Hicham Mahboubi ◽  
Ossama Moujaber ◽  
Mohamed Kodiha ◽  
Ursula Stochaj
Keyword(s):  
Stress Response ◽  
Cellular Stress ◽  
Stress Granules ◽  
Biological Properties ◽  
Cellular Stress Response ◽  
Binding Domains ◽  
Hsp70 Family ◽  
Independent Functions

The co-chaperone HspBP1 interacts with members of the hsp70 family, but also provides chaperone-independent functions. We report here novel biological properties of HspBP1 that are relevant to the formation of cytoplasmic stress granules (SGs). SG assembly is a conserved reaction to environmental or pathological insults and part of the cellular stress response. Our study reveals that HspBP1 (1) is an integral SG constituent, and (2) a regulator of SG assembly. Oxidative stress relocates HspBP1 to SGs, where it co-localizes with granule marker proteins and polyA-RNA. Mass spectrometry and co-immunoprecipitation identified novel HspBP1-binding partners that are critical for SG biology. Specifically, HspBP1 associates with the SG proteins G3BP1, HuR and TIA-1/TIAR. HspBP1 also interacts with polyA-RNA in vivo and binds directly RNA homopolymers in vitro. Multiple lines of evidence and single-granule analyses demonstrate that HspBP1 is crucial for SG biogenesis. Thus, HspBP1 knockdown interferes with stress-induced SG assembly. By contrast, HspBP1 overexpression promotes SG formation in the absence of stress. Notably, the hsp70-binding domains of HspBP1 regulate SG production in unstressed cells. Taken together, we identified novel HspBP1 activities that control SG formation. These features expand HspBP1’s role in the cellular stress response and provide new mechanistic insights into SG biogenesis.

scholarly journals NAP1-Related Protein 1 (NRP1) has multiple interaction modes for chaperoning histones H2A-H2B

2020 ◽  
Vol 117 (48) ◽  
pp. 30391-30399
Author(s):  
Qiang Luo ◽  
Baihui Wang ◽  
Zhen Wu ◽  
Wen Jiang ◽  
Yueyue Wang ◽  
...  
Keyword(s):  
Interaction Mechanism ◽  
Histone Chaperones ◽  
Related Protein ◽  
Nucleosome Assembly ◽  
Nucleosome Assembly Protein ◽  
Vitro Binding ◽  
Multiple Interaction ◽  
Α Helix

Nucleosome Assembly Protein 1 (NAP1) family proteins are evolutionarily conserved histone chaperones that play important roles in diverse biological processes. In this study, we determined the crystal structure ofArabidopsisNAP1-Related Protein 1 (NRP1) complexed with H2A-H2B and uncovered a previously unknown interaction mechanism in histone chaperoning. Both in vitro binding and in vivo plant rescue assays proved that interaction mediated by the N-terminal α-helix (αN) domain is essential for NRP1 function. In addition, the C-terminal acidic domain (CTAD) of NRP1 binds to H2A-H2B through a conserved mode similar to other histone chaperones. We further extended previous knowledge of the NAP1-conserved earmuff domain by mapping the amino acids of NRP1 involved in association with H2A-H2B. Finally, we showed that H2A-H2B interactions mediated by αN, earmuff, and CTAD domains are all required for the effective chaperone activity of NRP1. Collectively, our results reveal multiple interaction modes of a NAP1 family histone chaperone and shed light on how histone chaperones shield H2A-H2B from nonspecific interaction with DNA.

scholarly journals The Carboxyl Terminus of Rtt109 Functions in Chaperone Control of Histone Acetylation

2013 ◽  
Vol 12 (5) ◽  
pp. 654-664 ◽  
Author(s):  
Ernest Radovani ◽  
Matthew Cadorin ◽  
Tahireh Shams ◽  
Suzan El-Rass ◽  
Abdel R. Karsou ◽  
...  
Keyword(s):  
Histone Acetyltransferase ◽  
Histone H3 ◽  
Chromatin Assembly ◽  
Carboxyl Terminus ◽  
Histone Chaperones ◽  
Content Type ◽  
Histone H3 Acetylation ◽  
H3 Acetylation

ABSTRACT Rtt109 is a fungal histone acetyltransferase (HAT) that catalyzes histone H3 acetylation functionally associated with chromatin assembly. Rtt109-mediated H3 acetylation involves two histone chaperones, Asf1 and Vps75. In vivo , Rtt109 requires both chaperones for histone H3 lysine 9 acetylation (H3K9ac) but only Asf1 for full H3K56ac. In vitro , Rtt109-Vps75 catalyzes both H3K9ac and H3K56ac, whereas Rtt109-Asf1 catalyzes only H3K56ac. In this study, we extend the in vitro chaperone-associated substrate specificity of Rtt109 by showing that it acetylates vertebrate linker histone in the presence of Vps75 but not Asf1. In addition, we demonstrate that in Saccharomyces cerevisiae a short basic sequence at the carboxyl terminus of Rtt109 (Rtt109C) is required for H3K9ac in vivo . Furthermore, through in vitro and in vivo studies, we demonstrate that Rtt109C is required for optimal H3K56ac by the HAT in the presence of full-length Asf1. When Rtt109C is absent, Vps75 becomes important for H3K56ac by Rtt109 in vivo . In addition, we show that lysine 290 (K290) in Rtt109 is required in vivo for Vps75 to enhance the activity of the HAT. This is the first in vivo evidence for a role for Vps75 in H3K56ac. Taken together, our results contribute to a better understanding of chaperone control of Rtt109-mediated H3 acetylation.

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