Histone Chaperone as Coactivator of Chromatin Transcription: Role of Acetylation

2009 ◽  
pp. 263-278 ◽  
Author(s):  
Shrikanth S. Gadad ◽  
Jayasha Shandilya ◽  
Venkatesh Swaminathan ◽  
Tapas K. Kundu
Keyword(s):  
Histone Chaperone

scholarly journals Phosphorylation in the accessory domain of yeast histone chaperone protein 1 exposes the nuclear export signal sequence

2021 ◽  
Author(s):  
Sho Ashida ◽  
Rikuri Morita ◽  
Yasuteru Shigeta ◽  
Ryuhei Harada
Keyword(s):  
Cell Nucleus ◽  
Nuclear Export ◽  
Signal Sequence ◽  
Nuclear Export Signal ◽  
Md Simulations ◽  
Histone Chaperone ◽  
Chaperone Protein ◽  
Accessory Domain ◽  
Export Signal

Histone is a scaffold protein that constitutes nucleosomes with DNA in the cell nucleus. When forming histone, hetero octamer is assisted by histone chaperone proteins. As a histone chaperone protein, the crystal structure of yeast nucleosome assembly protein (yNap1) has been determined. For yNap1, a nuclear export signal/sequence (NES) has been identified as a part of the long -helix. Experimental evidence via mutagenesis on budding yeast suggests the NES is necessary for transport out from the cell nucleus. However, the NES is masked by a region defined as an accessory domain (AD). In addition, the role of the AD in nuclear transport has not been elucidated yet. To address the role of the AD, we focused on phosphorylation in the AD because proteome experiments have identified multiple phosphorylation sites of yNap1. To computationally treat phosphorylation, we performed all-atom molecular dynamics (MD) simulations for a set of non-phosphorylated and phosphorylated yNap1 (Nap1-nonP and Nap1-P). As an analysis, we addressed how the NES is exposed to the protein surface by measuring its solvent-access surface area (SASA). As a result, there was a difference in the SASA distributions between both systems. Quantitatively, the median of the SASA distribution of Nap1-P was greater than that of Nap1-nonP, meaning that phosphorylation in the AD exposed to the NES, resulting in increasing its accessibility. In conclusion, yNap1 might modulate the accessibility of the NES by dislocating the AD through phosphorylation.

The Arabidopsis Histone Chaperone FACT: Role of the HMG-Box Domain of SSRP1

2018 ◽  
Vol 430 (17) ◽  
pp. 2747-2759 ◽  
Author(s):  
Alexander Pfab ◽  
Jesper T. Grønlund ◽  
Philipp Holzinger ◽  
Gernot Längst ◽  
Klaus D. Grasser
Keyword(s):  
Histone Chaperone ◽  
Hmg Box

scholarly journals The Fission Yeast HIRA Histone Chaperone Is Required for Promoter Silencing and the Suppression of Cryptic Antisense Transcripts

2009 ◽  
Vol 29 (18) ◽  
pp. 5158-5167 ◽  
Author(s):  
Holly E. Anderson ◽  
Josephine Wardle ◽  
Şenay Vural Korkut ◽  
Heather E. Murton ◽  
Luis López-Maury ◽  
...  
Keyword(s):  
Fission Yeast ◽  
Histone Chaperone ◽  
Double Strand Breaks ◽  
Histone Chaperones ◽  
Antisense Transcripts ◽  
Strand Breaks ◽  
Bona Fide ◽  
Nuclear Exosome ◽  
Yeast Genes

ABSTRACT The assembly of nucleosomes by histone chaperones is an important component of transcriptional regulation. Here, we have assessed the global roles of the HIRA histone chaperone in Schizosaccharomyces pombe. Microarray analysis indicates that inactivation of the HIRA complex results in increased expression of at least 4% of fission yeast genes. HIRA-regulated genes overlap with those which are normally repressed in vegetatively growing cells, such as targets of the Clr6 histone deacetylase and silenced genes located in subtelomeric regions. HIRA is also required for silencing of all 13 intact copies of the Tf2 long terminal repeat (LTR) retrotransposon. However, the role of HIRA is not restricted to bona fide promoters, because HIRA also suppresses noncoding transcripts from solo LTR elements and spurious antisense transcripts from cryptic promoters associated with transcribed regions. Furthermore, the HIRA complex is essential in the absence of the quality control provided by nuclear exosome-mediated degradation of illegitimate transcripts. This suggests that HIRA restricts genomic accessibility, and consistent with this, the chromosomes of cells lacking HIRA are more susceptible to genotoxic agents that cause double-strand breaks. Thus, the HIRA histone chaperone is required to maintain the protective functions of chromatin.

scholarly journals Potential role of the histone chaperone, CAF-1, in transcription

BMB Reports ◽  
2009 ◽  
Vol 42 (4) ◽  
pp. 227-231 ◽  
Author(s):  
Hye-Jin Kim ◽  
Ja-Hwan Seol ◽  
Eun-Jung Cho
Keyword(s):  
Potential Role ◽  
Histone Chaperone

scholarly journals The role of FACT in managing chromatin: disruption, assembly, or repair?

2020 ◽  
Vol 48 (21) ◽  
pp. 11929-11941
Author(s):  
Tim Formosa ◽  
Fred Winston
Keyword(s):  
Dna Repair ◽  
Dna Replication ◽  
Normal State ◽  
Elongation Factor ◽  
Histone Chaperone ◽  
The Core ◽  
Transcription Elongation Factor ◽  
Differentiated Cells ◽  
Chromatin Integrity

Abstract FACT (FAcilitates Chromatin Transcription) has long been considered to be a transcription elongation factor whose ability to destabilize nucleosomes promotes RNAPII progression on chromatin templates. However, this is just one function of this histone chaperone, as FACT also functions in DNA replication. While broadly conserved among eukaryotes and essential for viability in many organisms, dependence on FACT varies widely, with some differentiated cells proliferating normally in its absence. It is therefore unclear what the core functions of FACT are, whether they differ in different circumstances, and what makes FACT essential in some situations but not others. Here, we review recent advances and propose a unifying model for FACT activity. By analogy to DNA repair, we propose that the ability of FACT to both destabilize and assemble nucleosomes allows it to monitor and restore nucleosome integrity as part of a system of chromatin repair, in which disruptions in the packaging of DNA are sensed and returned to their normal state. The requirement for FACT then depends on the level of chromatin disruption occurring in the cell, and the cell's ability to tolerate packaging defects. The role of FACT in transcription would then be just one facet of a broader system for maintaining chromatin integrity.

scholarly journals The Cac1 subunit of histone chaperone CAF-1 organizes CAF-1-H3/H4 architecture and tetramerizes histones

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Wallace H Liu ◽  
Sarah C Roemer ◽  
Yeyun Zhou ◽  
Zih-Jie Shen ◽  
Briana K Dennehey ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Histone Chaperone ◽  
Protein Protein Interactions ◽  
Rich Domain ◽  
C Terminus ◽  
Assembly Factor ◽  
Hydrogen Deuterium ◽  
And Function ◽  
Minimal Region

The histone chaperone Chromatin Assembly Factor 1 (CAF-1) deposits tetrameric (H3/H4)2 histones onto newly-synthesized DNA during DNA replication. To understand the mechanism of the tri-subunit CAF-1 complex in this process, we investigated the protein-protein interactions within the CAF-1-H3/H4 architecture using biophysical and biochemical approaches. Hydrogen/deuterium exchange and chemical cross-linking coupled to mass spectrometry reveal interactions that are essential for CAF-1 function in budding yeast, and importantly indicate that the Cac1 subunit functions as a scaffold within the CAF-1-H3/H4 complex. Cac1 alone not only binds H3/H4 with high affinity, but also promotes histone tetramerization independent of the other subunits. Moreover, we identify a minimal region in the C-terminus of Cac1, including the structured winged helix domain and glutamate/aspartate-rich domain, which is sufficient to induce (H3/H4)2 tetramerization. These findings reveal a key role of Cac1 in histone tetramerization, providing a new model for CAF-1-H3/H4 architecture and function during eukaryotic replication.

scholarly journals Role of histone chaperone Nucleophosmin‐mediated transcriptional regulation in oral tumorigenesis

2019 ◽  
Vol 33 (S1) ◽  
Author(s):  
Suchismita Dey ◽  
Parijat Senapati ◽  
Aditya Bhattacharya ◽  
Deepthi Sudarshan ◽  
Sadhan Das ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Histone Chaperone

scholarly journals Distinct role of histone chaperone Asf1a and Asf1b during fertilization and pre-implantation embryonic development in mice

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Xuemei Wang ◽  
Lu Wang ◽  
Jie Dou ◽  
Tianjiao Yu ◽  
Pengbo Cao ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Histone Chaperone ◽  
Blastocyst Stage ◽  
Nuclear Accumulation ◽  
Cell Stage ◽  
Developmental Potential ◽  
Oct4 Expression ◽  
Real Time Quantitative Pcr ◽  
Histone H3.3

Abstract Background Asf1 is a well-conserved histone chaperone that regulates multiple cellular processes in different species. Two paralogous genes, Asf1a and Asf1b exist in mammals, but their role during fertilization and early embryogenesis remains to be investigated further. Methods We analyzed the dynamics of histone chaperone Asf1a and Asf1b in oocytes and pre-implantation embryos in mice by immunofluorescence and real-time quantitative PCR, and further investigated the role of Asf1a and Asf1b during fertilization and pre-implantation development by specific Morpholino oligos-mediated knock down approach. Results Immunofluorescence with specific antibodies revealed that both Asf1a and Asf1b were deposited in the nuclei of fully grown oocytes, accumulated abundantly in zygote and 2-cell embryonic nuclei, but turned low at 4-cell stage embryos. In contrast to the weak but definite nuclear deposition of Asf1a, Asf1b disappeared from embryonic nuclei at morula and blastocyst stages. The knockdown of Asf1a and Asf1b by specific Morpholino oligos revealed that Asf1a but not Asf1b was required for the histone H3.3 assembly in paternal pronucleus. However, knockdown of either Asf1a or Asf1b expression decreased developmental potential of pre-implantation embryos. Furthermore, while Asf1a KD severely reduced H3K56 acetylation level and the expression of Oct4 in blastocyst stage embryos, Asf1b KD almost eliminated nuclear accumulation of proliferating cell marker-PCNA in morula stage embryos. These results suggested that histone chaperone Asf1a and Asf1b play distinct roles during fertilization and pre-implantation development in mice. Conclusions Our data suggested that both Asf1a and Asf1b are required for pre-implantation embryonic development. Asf1a regulates H3K56ac levels and Oct4 expression, while Asf1b safeguards pre-implantation embryo development by regulating cell proliferation. We also showed that Asf1a, but not Asf1b, was necessary for the assembly of histone H3.3 in paternal pronuclei after fertilization.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor
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