Nucleosome assembly proteins and their interacting proteins in neuronal differentiation

2013 ◽  
Vol 534 (1-2) ◽  
pp. 20-26 ◽  
Author(s):  
Mikaël Attia ◽  
Christophe Rachez ◽  
Philip Avner ◽  
Ute Christine Rogner
2007 ◽  
Vol 27 (17) ◽  
pp. 6093-6102 ◽  
Author(s):  
Mikaël Attia ◽  
Christophe Rachez ◽  
Antoine De Pauw ◽  
Philip Avner ◽  
Ute Christine Rogner

ABSTRACT The deletion of the neuronal Nap1l2 (nucleosome assembly protein 1-like 2) gene in mice causes neural tube defects. We demonstrate here that this phenotype correlates with deficiencies in differentiation and increased maintenance of the neural stem cell stage. Nap1l2 associates with chromatin and interacts with histones H3 and H4. Loss of Nap1l2 results in decreased histone acetylation activity, leading to transcriptional changes in differentiating neurons, which include the marked downregulation of the Cdkn1c (cyclin-dependent kinase inhibitor 1c) gene. Cdkn1c expression normally increases during neuronal differentiation, and this correlates with the specific recruitment of the Nap1l2 protein and an increase in acetylated histone H3K9/14 at the site of Cdkn1c transcription. These results lead us to suggest that the Nap1l2 protein plays an important role in regulating transcription in developing neurons via the control of histone acetylation. Our data support the idea that neuronal nucleosome assembly proteins mediate cell-type-specific mechanisms of establishment/modification of a chromatin-permissive state that can affect neurogenesis and neuronal survival.


2000 ◽  
Vol 20 (23) ◽  
pp. 8933-8943 ◽  
Author(s):  
Noriko Shikama ◽  
Ho Man Chan ◽  
Marija Krstic-Demonacos ◽  
Linda Smith ◽  
Chang-Woo Lee ◽  
...  

ABSTRACT The p300/CREB-binding protein (CBP) family of proteins consists of coactivators that influence the activity of a wide variety of transcription factors. Although the mechanisms that allow p300/CBP proteins to achieve transcriptional control are not clear, it is believed that the regulation of chromatin is an important aspect of the process. Here, we describe a new level of p300-dependent control mediated through the functional interaction between p300/CBP and members of the family of nucleosome assembly proteins (NAP), which includes NAP1, NAP2, and TAF1. We find that NAP proteins, which have previously been implicated in the regulation of transcription factor binding to chromatin, augment the activity of different p300 targets, including p53 and E2F, through a process that is likely to involve the physical interaction between p300 and NAP. NAP proteins can form oligomers, and the results show that NAP proteins can bind to both core histones and p300 coactivator proteins, perhaps in a multicomponent ternary complex. We also provide data in support of the idea that histones can influence the interaction between p300 and NAP protein. These results argue that NAP is a functionally important component of the p300 coactivator complex and suggest that NAP may serve as a point of integration between transcriptional coactivators and chromatin.


Blood ◽  
2005 ◽  
Vol 106 (2) ◽  
pp. 514-520 ◽  
Author(s):  
Anita Abu-Daya ◽  
Wendy M. Steer ◽  
Alexandra F. Trollope ◽  
Christine E. Friedeberg ◽  
Roger K. Patient ◽  
...  

Abstract Nucleosome assembly proteins (NAPs) bind core histones, facilitate chromatin remodeling, and can act as transcriptional coactivators. We previously described the isolation of a Xenopus NAP1-like (xNAP1L) cDNA, which encodes a member of this protein family. Its zygotic expression is restricted to neural cells, the outer cells of the ventral blood island (VBIs), and the ectoderm overlying the blood precursors. Here, we report that depletion of zygotic xNAP1L in embryos produces no obvious morphologic phenotype, but ablates α-globin mRNA expression in the VBIs. Transcript levels of the hematopoietic precursor genes SCL and Xaml (Runx-1) are also reduced in the VBIs. SCL expression can be rescued by injection of xNAP1L mRNA into the ectoderm, showing that the effect of xNAP1L can be non–cell autonomous. Fli1 and Hex, genes expressed in hemangioblasts but subsequently endothelial markers, were unaffected, suggesting that xNAP1L is required for the hematopoietic lineage specifically. Our data are consistent with a requirement for xNAP1L upstream of SCL, and injection of SCL mRNA into xNAP1L-depleted embryos rescues α-globin expression. Thus, xNAP1L, which belongs to a family of proteins previously believed to have general roles, has a specific function in hematopoiesis.


1996 ◽  
Vol 74 (4) ◽  
pp. 281-285 ◽  
Author(s):  
T.K. Watanabe ◽  
T. Fujiwara ◽  
Y. Nakamura ◽  
Y. Hirai ◽  
H. Maekawa ◽  
...  

Author(s):  
Christopher Warren ◽  
Jeffrey B. Bonanno ◽  
Steven C. Almo ◽  
David Shechter

Chromatin is the complex assembly of nucleic acids and proteins that makes up the physiological form of the eukaryotic genome. The nucleosome is the fundamental repeating unit of chromatin, and is composed of ∼147 bp of DNA wrapped around a histone octamer formed by two copies of each core histone: H2A, H2B, H3 and H4. Prior to nucleosome assembly, and during histone eviction, histones are typically assembled into soluble H2A/H2B dimers and H3/H4 dimers and tetramers. A multitude of factors interact with soluble histone dimers and tetramers, including chaperones, importins, histone-modifying enzymes and chromatin-remodeling enzymes. It is still unclear how many of these proteins recognize soluble histones; therefore, there is a need for new structural tools to study non-nucleosomal histones. Here, a single-chain, tailless Xenopus H2A/H2B dimer was created by directly fusing the C-terminus of H2B to the N-terminus of H2A. It is shown that this construct (termed scH2BH2A) is readily expressed in bacteria and can be purified under non-denaturing conditions. A 1.31 Å resolution crystal structure of scH2BH2A shows that it adopts a conformation that is nearly identical to that of nucleosomal H2A/H2B. This new tool is likely to facilitate future structural studies of many H2A/H2B-interacting proteins.


2021 ◽  
Vol 23 (1) ◽  
pp. 368
Author(s):  
Jana Fulnečková ◽  
Ladislav Dokládal ◽  
Karolína Kolářová ◽  
Martina Nešpor Dadejová ◽  
Klára Procházková ◽  
...  

Telomerase, an essential enzyme that maintains chromosome ends, is important for genome integrity and organism development. Various hypotheses have been proposed in human, ciliate and yeast systems to explain the coordination of telomerase holoenzyme assembly and the timing of telomerase performance at telomeres during DNA replication or repair. However, a general model is still unclear, especially pathways connecting telomerase with proposed non-telomeric functions. To strengthen our understanding of telomerase function during its intracellular life, we report on interactions of several groups of proteins with the Arabidopsis telomerase protein subunit (AtTERT) and/or a component of telomerase holoenzyme, POT1a protein. Among these are the nucleosome assembly proteins (NAP) and the minichromosome maintenance (MCM) system, which reveal new insights into the telomerase interaction network with links to telomere chromatin assembly and replication. A targeted investigation of 176 candidate proteins demonstrated numerous interactions with nucleolar, transport and ribosomal proteins, as well as molecular chaperones, shedding light on interactions during telomerase biogenesis. We further identified protein domains responsible for binding and analyzed the subcellular localization of these interactions. Moreover, additional interaction networks of NAP proteins and the DOMINO1 protein were identified. Our data support an image of functional telomerase contacts with multiprotein complexes including chromatin remodeling and cell differentiation pathways.


2011 ◽  
Vol 317 (20) ◽  
pp. 2853-2863 ◽  
Author(s):  
Masashi Okada ◽  
Yasukazu Hozumi ◽  
Tohru Ichimura ◽  
Toshiaki Tanaka ◽  
Hiroshi Hasegawa ◽  
...  

2020 ◽  
Author(s):  
Christopher Warren ◽  
Jeffrey B. Bonanno ◽  
Steven C. Almo ◽  
David Shechter

ABSTRACTChromatin is the complex assembly of nucleic acids and proteins that makes up the physiological form of the eukaryotic genome. The nucleosome is the fundamental repeating unit of chromatin, composed of ~147bp of DNA wrapped around a histone octamer formed by two copies of each core histone: H2A, H2B, H3 and H4. Prior to nucleosome assembly, and during histone eviction, histones are typically assembled into soluble H2A/H2B dimers and H3/H4 dimers and tetramers. A multitude of factors interact with soluble histone dimers and tetramers, including chaperones, importins, histone modifying enzymes, and chromatin remodeling enzymes. It is still unclear how many of these proteins recognize soluble histones; therefore, there is a need for new structural tools to study non-nucleosomal histones. Here we created a single-chain, tailless Xenopus H2A/H2B dimer by directly fusing the C-terminus of H2B to the N-terminus of H2A. We show that this construct (termed scH2BH2A) is readily expressed in bacteria and can be purified under non-denaturing conditions. A 1.31Å crystal structure of scH2BH2A shows that it adopts a conformation nearly identical to nucleosomal H2A/H2B. This new tool will facilitate future structural studies of a multitude of H2A/H2B-interacting proteins.


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