scholarly journals Telomerase Interaction Partners–Insight from Plants

2021 ◽  
Vol 23 (1) ◽  
pp. 368
Author(s):  
Jana Fulnečková ◽  
Ladislav Dokládal ◽  
Karolína Kolářová ◽  
Martina Nešpor Dadejová ◽  
Klára Procházková ◽  
...  
Keyword(s):  
Ribosomal Proteins ◽  
Interaction Network ◽  
Nucleosome Assembly ◽  
Protein Subunit ◽  
Minichromosome Maintenance ◽  
Interaction Partners ◽  
Essential Enzyme ◽  
Telomere Chromatin ◽  
Differentiation Pathways ◽  
Assembly Proteins

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.

scholarly journals Role of the Ndc1 interaction network in yeast nuclear pore complex assembly and maintenance

2009 ◽  
Vol 185 (3) ◽  
pp. 475-491 ◽  
Author(s):  
Evgeny Onischenko ◽  
Leslie H. Stanton ◽  
Alexis S. Madrid ◽  
Thomas Kieselbach ◽  
Karsten Weis
Keyword(s):  
Nuclear Pore Complex ◽  
Structural Integrity ◽  
Fluorescent Protein ◽  
Interaction Network ◽  
Nucleocytoplasmic Transport ◽  
Nuclear Pore ◽  
Binding Partners ◽  
Interaction Partners ◽  
Redundant Functions

The nuclear pore complex (NPC) mediates all nucleocytoplasmic transport, yet its structure and biogenesis remain poorly understood. In this study, we have functionally characterized interaction partners of the yeast transmembrane nucleoporin Ndc1. Ndc1 forms a distinct complex with the transmembrane proteins Pom152 and Pom34 and two alternative complexes with the soluble nucleoporins Nup53 and Nup59, which in turn bind to Nup170 and Nup157. The transmembrane and soluble Ndc1-binding partners have redundant functions at the NPC, and disruption of both groups of interactions causes defects in Ndc1 targeting and in NPC structure accompanied by significant pore dilation. Using photoconvertible fluorescent protein fusions, we further show that the depletion of Pom34 in cells that lack NUP53 and NUP59 blocks new NPC assembly and leads to the reversible accumulation of newly made nucleoporins in cytoplasmic foci. Therefore, Ndc1 together with its interaction partners are collectively essential for the biosynthesis and structural integrity of yeast NPCs.

scholarly journals Functional Interaction between Nucleosome Assembly Proteins and p300/CREB-Binding Protein Family Coactivators

2000 ◽  
Vol 20 (23) ◽  
pp. 8933-8943 ◽  
Author(s):  
Noriko Shikama ◽  
Ho Man Chan ◽  
Marija Krstic-Demonacos ◽  
Linda Smith ◽  
Chang-Woo Lee ◽  
...  
Keyword(s):  
Transcriptional Control ◽  
Binding Protein ◽  
Regulation Of Transcription ◽  
Physical Interaction ◽  
Creb Binding Protein ◽  
Nucleosome Assembly ◽  
Functional Interaction ◽  
The Family ◽  
Core Histones ◽  
Assembly Proteins

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.

scholarly journals Zygotic nucleosome assembly protein–like 1 has a specific, non–cell autonomous role in hematopoiesis

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 ◽  
...  
Keyword(s):  
Chromatin Remodeling ◽  
Neural Cells ◽  
Nucleosome Assembly ◽  
Globin Mrna ◽  
Blood Island ◽  
Nucleosome Assembly Protein ◽  
Hematopoietic Lineage ◽  
Core Histones ◽  
Hematopoietic Precursor ◽  
Assembly Proteins

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.

Cloning, expression pattern and mapping to Xq of NAP1 L3, a gene encoding a peptide homologous to human and yeast nucleosome assembly proteins

1996 ◽  
Vol 74 (4) ◽  
pp. 281-285 ◽  
Author(s):  
T.K. Watanabe ◽  
T. Fujiwara ◽  
Y. Nakamura ◽  
Y. Hirai ◽  
H. Maekawa ◽  
...  
Keyword(s):  
Expression Pattern ◽  
Nucleosome Assembly ◽  
Gene Encoding ◽  
Assembly Proteins

scholarly journals Nap1l2 Promotes Histone Acetylation Activity during Neuronal Differentiation

2007 ◽  
Vol 27 (17) ◽  
pp. 6093-6102 ◽  
Author(s):  
Mikaël Attia ◽  
Christophe Rachez ◽  
Antoine De Pauw ◽  
Philip Avner ◽  
Ute Christine Rogner
Keyword(s):  
Histone Acetylation ◽  
Neuronal Differentiation ◽  
Nucleosome Assembly ◽  
Cell Type ◽  
Cell Stage ◽  
Transcriptional Changes ◽  
Cell Type Specific ◽  
Mediate Cell ◽  
Developing Neurons ◽  
Assembly Proteins

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.

scholarly journals An interaction network of RNA-binding proteins involved in Drosophila oogenesis

2020 ◽  
Author(s):  
Prashali Bansal ◽  
Johannes Madlung ◽  
Kristina Schaaf ◽  
Boris Macek ◽  
Fulvia Bono
Keyword(s):  
Translational Regulation ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Direct Interaction ◽  
Interaction Network ◽  
Splicing Factors ◽  
Mrna Regulation ◽  
Interaction Partners ◽  
Maternal Transcripts

AbstractDuring Drosophila oogenesis, the localization and translational regulation of maternal transcripts relies on RNA-binding proteins (RBPs). Many of these RBPs localize several mRNAs and may have additional direct interaction partners to regulate their functions. Using immunoprecipitation from whole Drosophila ovaries coupled to mass spectrometry, we examined protein-protein associations of 6 GFP-tagged RBPs expressed at physiological levels. Analysis of the interaction network and further validation in human cells allowed us to identify 26 previously unknown associations, besides recovering several well characterized interactions. We identified interactions between RBPs and several splicing factors, providing links between nuclear and cytoplasmic events of mRNA regulation. Additionally, components of the translational and RNA decay machineries were selectively co-purified with some baits, suggesting a mechanism for how RBPs may regulate maternal transcripts. Given the evolutionary conservation of the studied RBPs, the interaction network presented here provides the foundation for future functional and structural studies of mRNA localization across metazoans.

scholarly journals An Interaction Network of RNA-Binding Proteins Involved in Drosophila Oogenesis

2020 ◽  
Vol 19 (9) ◽  
pp. 1485-1502
Author(s):  
Prashali Bansal ◽  
Johannes Madlung ◽  
Kristina Schaaf ◽  
Boris Macek ◽  
Fulvia Bono
Keyword(s):  
Translational Regulation ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Direct Interaction ◽  
Interaction Network ◽  
Splicing Factors ◽  
Mrna Regulation ◽  
Interaction Partners ◽  
Maternal Transcripts

During Drosophila oogenesis, the localization and translational regulation of maternal transcripts relies on RNA-binding proteins (RBPs). Many of these RBPs localize several mRNAs and may have additional direct interaction partners to regulate their functions. Using immunoprecipitation from whole Drosophila ovaries coupled to mass spectrometry, we examined protein-protein associations of 6 GFP-tagged RBPs expressed at physiological levels. Analysis of the interaction network and further validation in human cells allowed us to identify 26 previously unknown associations, besides recovering several well characterized interactions. We identified interactions between RBPs and several splicing factors, providing links between nuclear and cytoplasmic events of mRNA regulation. Additionally, components of the translational and RNA decay machineries were selectively co-purified with some baits, suggesting a mechanism for how RBPs may regulate maternal transcripts. Given the evolutionary conservation of the studied RBPs, the interaction network presented here provides the foundation for future functional and structural studies of mRNA localization across metazoans.

scholarly journals MCM2 partial silencing inhibits apical dominance and promotes chlorophyll pigmentation in tomato

2019 ◽  
Author(s):  
Ma-ye Gao ◽  
Jin Liang ◽  
Hai-ting Liu ◽  
Di-an Ni
Keyword(s):  
Dna Replication ◽  
Apical Dominance ◽  
Expression Level ◽  
Loss Of Function ◽  
Wild Type ◽  
Protein Subunit ◽  
Minichromosome Maintenance ◽  
Chlorophyll Accumulation ◽  
Transgenic Tomato Plants ◽  
The Relationship

Background: We have previously combined loss- and gain-of-function approaches to investigate the function of Arabidopsis minichromosome maintenance (MCM) protein subunit 2 (MCM2). However MCM2 loss of function leads to the death of embryos, thus precluding the analysis of homozygous MCM2 mutants. Methods: To further understand the function of MCM2, we generated transgenic tomato plants via RNA interference silencing. And microarray slide hybridization was used to compare gene expression level between LeMCM2 -silenced lines and wild-type plants. Results: We obtained 4 LeMCM2 -silenced lines. The expression level in LeMCM2 -silenced lines was 20-80% of that of wild-type. And LeMCM2 -silenced lines display loss of apical dominance, enhanced chlorophyll accumulation and reduced leaf cell endoduplication. In addition, the expression levels of genes involved in DNA replication was altered in LeMCM2 -silenced lines significantly. Conclusion: In general, the data described here provided additional evidence for the relationship between genes involved in DNA replication and apical dominance and chlorophyll pigmentation.

scholarly journals Motif clustering with implications for transcription factor interactions

2015 ◽  
Author(s):  
Jan Grau ◽  
Ivo Grosse ◽  
Stefan Posch ◽  
Jens Keilwagen
Keyword(s):  
Rna Polymerase Ii ◽  
Motif Discovery ◽  
De Novo ◽  
Interaction Network ◽  
Data Sets ◽  
Interaction Partners ◽  
De Novo Motif Discovery ◽  
Motif Clustering ◽  
Data Source ◽  
Factor Interactions

High-throughput data, for instance ChIP-seq data, measure binding of transcription factors (TFs) or other proteins to DNA and have become a widespread data source for de-novo motif discovery. Often, several ChIP-seq data sets study the same TF under different conditions resulting in several, potentially redundant motifs, which demands for identification and clustering of similar motifs. Here, we propose a refined measure of motif similarity based on the correlation between score profiles on de Bruijn sequences. We demonstrate the utility of the proposed measure in benchmark studies on artificial motifs and motifs discovered from ENCODE ChIP-seq data. We use this measure to cluster motifs discovered from 757 different ENCODE ChIP-seq data sets for 166 TFs and RNA-polymerase II and III. Based on this clustering, we derive a TF interaction network that reflects many known TF-TF interactions, but also reveals novel putative interaction partners.

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