Functional Requirement of Noncoding Y RNAs for Human Chromosomal DNA Replication

ABSTRACT Noncoding RNAs are recognized increasingly as important regulators of fundamental biological processes, such as gene expression and development, in eukaryotes. We report here the identification and functional characterization of the small noncoding human Y RNAs (hY RNAs) as novel factors for chromosomal DNA replication in a human cell-free system. In addition to protein fractions, hY RNAs are essential for the establishment of active chromosomal DNA replication forks in template nuclei isolated from late-G1-phase human cells. Specific degradation of hY RNAs leads to the inhibition of semiconservative DNA replication in late-G1-phase template nuclei. This inhibition is negated by resupplementation of hY RNAs. All four hY RNAs (hY1, hY3, hY4, and hY5) can functionally substitute for each other in this system. Mutagenesis of hY1 RNA showed that the binding site for Ro60 protein, which is required for Ro RNP assembly, is not essential for DNA replication. Degradation of hY1 RNA in asynchronously proliferating HeLa cells by RNA interference reduced the percentages of cells incorporating bromodeoxyuridine in vivo. These experiments implicate a functional role for hY RNAs in human chromosomal DNA replication.

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Nuclease dead Cas9 is a programmable roadblock for DNA replication

10.1101/455543 ◽

2018 ◽

Cited By ~ 1

Author(s):

Kelsey Whinn ◽

Gurleen Kaur ◽

Jacob S. Lewis ◽

Grant Schauer ◽

Stefan Müller ◽

...

Keyword(s):

Dna Replication ◽

Single Molecule ◽

Replication Fork ◽

Molecular Machines ◽

Replication Forks ◽

Chromosomal Dna ◽

Single Molecule Level ◽

Replication Fork Arrest

DNA replication occurs on chromosomal DNA while processes such as DNA repair, recombination and transcription continue. However, we have limited experimental tools to study the consequences of collisions between DNA-bound molecular machines. Here, we repurpose a catalytically inactivated Cas9 (dCas9) construct fused to the photo-stable dL5 protein fluoromodule as a novel, targetable protein-DNA roadblock for studying replication fork arrest at the single-molecule level in vitro as well as in vivo. We find that the specifically bound dCas9–guideRNA complex arrests viral, bacterial and eukaryotic replication forks in vitro.

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Characterization of Cdc47p-minichromosome maintenance complexes in Saccharomyces cerevisiae: identification of Cdc45p as a subunit.

Molecular and Cellular Biology ◽

10.1128/mcb.17.10.5867 ◽

1997 ◽

Vol 17 (10) ◽

pp. 5867-5875 ◽

Cited By ~ 42

Author(s):

S Dalton ◽

B Hopwood

Keyword(s):

Saccharomyces Cerevisiae ◽

Cell Cycle ◽

Dna Replication ◽

Chromosomal Dna ◽

Minichromosome Maintenance ◽

Rate Limiting Step ◽

A Subunit

Cdc47p is a member of the minichromosome maintenance (MCM) family of polypeptides, which have a role in the early stages of chromosomal DNA replication. Here, we show that Cdc47p assembles into stable complexes with two other members of the MCM family, Cdc46p and Mcm3p. The assembly of Cdc47p into complexes with Cdc46p does not appear to be cell cycle regulated, making it unlikely that these interactions per se are a rate-limiting step in the control of S phase. Cdc45p is also shown to interact with Cdc47p in vivo and to be a component of high-molecular-weight MCM complexes in cell lysates. Like MCM polypeptides, Cdc45p is essential for the initiation of chromosomal DNA replication in Saccharomyces cerevisiae; however, Cdc45p remains in the nucleus throughout the cell cycle, whereas MCMs are nuclear only during G1. We characterize two mutations in CDC47 and CDC46 which arrest cells with unduplicated DNA as a result of single base substitutions. The corresponding amino acid substitutions in Cdc46p and Cdc47p severely reduce the ability of these polypeptides to assemble in a complex with each other in vivo and in vitro. This argues that assembly of Cdc47p into complexes with other MCM polypeptides is important for its role in the initiation of chromosomal DNA replication.

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Functional characterization of human brown adipose tissue metabolism

Biochemical Journal ◽

10.1042/bcj20190464 ◽

2020 ◽

Vol 477 (7) ◽

pp. 1261-1286 ◽

Cited By ~ 3

Author(s):

Marie Anne Richard ◽

Hannah Pallubinsky ◽

Denis P. Blondin

Keyword(s):

Adipose Tissue ◽

Brown Adipose Tissue ◽

Functional Characterization ◽

Human Infants ◽

Positron Emission ◽

Brown Adipose ◽

Treatment Of Obesity ◽

And Function

Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.

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Functional characterization of a full length pregnane X receptor, expression in vivo, and identification of PXR alleles, in Zebrafish (Danio rerio)

Aquatic Toxicology ◽

10.1016/j.aquatox.2013.09.014 ◽

2013 ◽

Vol 142-143 ◽

pp. 447-457 ◽

Cited By ~ 30

Author(s):

Afonso C.D. Bainy ◽

Akira Kubota ◽

Jared V. Goldstone ◽

Roger Lille-Langøy ◽

Sibel I. Karchner ◽

...

Keyword(s):

Danio Rerio ◽

Functional Characterization ◽

Pregnane X Receptor ◽

Full Length ◽

Receptor Expression

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Functional identification of ygiP as a positive regulator of the ttdA-ttdB-ygjE operon

Microbiology ◽

10.1099/mic.0.28753-0 ◽

2006 ◽

Vol 152 (7) ◽

pp. 2129-2135 ◽

Cited By ~ 17

Author(s):

Taku Oshima ◽

Francis Biville

Keyword(s):

Functional Characterization ◽

Anaerobic Growth ◽

Functional Identification ◽

New Members ◽

E Coli ◽

Inner Membrane Protein ◽

Tartrate Dehydratase

Functional characterization of unknown genes is currently a major task in biology. The search for gene function involves a combination of various in silico, in vitro and in vivo approaches. Available knowledge from the study of more than 21 LysR-type regulators in Escherichia coli has facilitated the classification of new members of the family. From sequence similarities and its location on the E. coli chromosome, it is suggested that ygiP encodes a lysR regulator controlling the expression of a neighbouring operon; this operon encodes the two subunits of tartrate dehydratase (TtdA, TtdB) and YgiE, an integral inner-membrane protein possibly involved in tartrate uptake. Expression of tartrate dehydratase, which converts tartrate to oxaloacetate, is required for anaerobic growth on glycerol as carbon source in the presence of tartrate. Here, it has been demonstrated that disruption of ygiP, ttdA or ygjE abolishes tartrate-dependent anaerobic growth on glycerol. It has also been shown that tartrate-dependent induction of the ttdA-ttdB-ygjE operon requires a functional YgiP.

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Functional Characterization of the mazEF Toxin-Antitoxin System in the Pathogenic Bacterium Agrobacterium tumefaciens

Microorganisms ◽

10.3390/microorganisms9051107 ◽

2021 ◽

Vol 9 (5) ◽

pp. 1107

Author(s):

Wonho Choi ◽

Yoshihiro Yamaguchi ◽

Ji-Young Park ◽

Sang-Hyun Park ◽

Hyeok-Won Lee ◽

...

Keyword(s):

Agrobacterium Tumefaciens ◽

Physiological Function ◽

Functional Characterization ◽

Site Directed Mutagenesis ◽

In Vitro Assays ◽

Cell Growth Inhibition ◽

The Right

Agrobacterium tumefaciens is a pathogen of various plants which transfers its own DNA (T-DNA) to the host plants. It is used for producing genetically modified plants with this ability. To control T-DNA transfer to the right place, toxin-antitoxin (TA) systems of A. tumefaciens were used to control the target site of transfer without any unintentional targeting. Here, we describe a toxin-antitoxin system, Atu0939 (mazE-at) and Atu0940 (mazF-at), in the chromosome of Agrobacterium tumefaciens. The toxin in the TA system has 33.3% identity and 45.5% similarity with MazF in Escherichia coli. The expression of MazF-at caused cell growth inhibition, while cells with MazF-at co-expressed with MazE-at grew normally. In vivo and in vitro assays revealed that MazF-at inhibited protein synthesis by decreasing the cellular mRNA stability. Moreover, the catalytic residue of MazF-at was determined to be the 24th glutamic acid using site-directed mutagenesis. From the results, we concluded that MazF-at is a type II toxin-antitoxin system and a ribosome-independent endoribonuclease. Here, we characterized a TA system in A. tumefaciens whose understanding might help to find its physiological function and to develop further applications.

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Functional Characterization of Interferon Regulation Element of Hepatitis B virus Genome In Vivo

Indian Journal of Virology ◽

10.1007/s13337-012-0091-2 ◽

2012 ◽

Vol 23 (3) ◽

pp. 278-285 ◽

Cited By ~ 2

Author(s):

Feng-Jun Liu ◽

En-Qiang Chen ◽

Qiao-Ling Zhou ◽

Tao-You Zhou ◽

Cong Liu ◽

...

Keyword(s):

Hepatitis B Virus ◽

Hepatitis B ◽

Functional Characterization ◽

Virus Genome ◽

B Virus

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Identification and functional characterization of legumain in amphioxus Branchiostoma belcheri

Bioscience Reports ◽

10.1042/bsr20090049 ◽

2009 ◽

Vol 30 (3) ◽

pp. 177-186 ◽

Cited By ~ 6

Author(s):

Lei Teng ◽

Hiroshi Wada ◽

Shicui Zhang

Keyword(s):

Functional Characterization ◽

Specific Substrate ◽

Glycosylation Sites ◽

Branchiostoma Belcheri ◽

Hen’S Egg ◽

Hind Gut ◽

Catalytic Dyad ◽

Pepstatin A

Legumain has been reported from diverse sources such as plants, parasites (animals) and mammals, but little is known in the lower chordates. The present study reports the first characterization of legumain cDNA from the protochordate Branchiostoma belcheri. The deduced 435-amino-acid-long protein is structurally characterized by the presence of a putative N-terminal signal peptide, a peptidase_C13 superfamily domain with the conserved Lys123-Gly124-Asp125 motif and catalytic dyad His153 and Cys195 and two potential Asn-glycosylation sites at Asn85 and Asn270. Phylogenetic analysis demonstrates that B. belcheri legumain forms an independent cluster together with ascidian legumain, and is positioned at the base of vertebrate legumains, suggesting that B. belcheri legumain gene may represent the archetype of vertebrate legumain genes. Both recombinant legumain expressed in yeast and endogenous legumain are able to be converted into active protein of ~37 kDa via a C-terminal autocleavage at acid pH values. The recombinant legumain efficiently degrades the legumain-specific substrate Z-Ala-Ala-Asn-MCA (benzyloxycarbonyl-L-alanyl-L-alanyl-L-asparagine-4-methylcoumaryl-7-amide) at optimum pH 5.5; and the enzymatic activity is inhibited potently by iodoacetamide and N-ethylmaleimide, partially by hen's-egg white cystatin, but not by E-64 [trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane], PMSF and pepstatin A. In addition, legumain is expressed in vivo in a tissue-specific manner, with main expression in the hepatic caecum and hind-gut of B. belcheri. Altogether, these results suggest that B. belcheri legumain plays a role in the degradation of macromolecules in food.

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Single-molecule binding characterization of primosomal protein PriA involved in replication restart

Physical Chemistry Chemical Physics ◽

10.1039/d1cp00638j ◽

2021 ◽

Author(s):

Tzu-Yu Lee ◽

Yi-Ching Li ◽

Min-Guan Lin ◽

Chwan-Deng Hsiao ◽

Hung-Wen Li

Keyword(s):

Dna Replication ◽

Dna Synthesis ◽

Single Molecule ◽

Replication Forks ◽

Bacterial Survival ◽

Dna Damages ◽

Replication Restart

DNA damages lead to stalled or collapsed replication forks. Replication restart primosomes re-initiate DNA synthesis at these stalled or collapsed DNA replication forks, which is important for bacterial survival. Primosomal...

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RNA Deregulation in Amyotrophic Lateral Sclerosis: The Noncoding Perspective

International Journal of Molecular Sciences ◽

10.3390/ijms221910285 ◽

2021 ◽

Vol 22 (19) ◽

pp. 10285

Author(s):

Pietro Laneve ◽

Paolo Tollis ◽

Elisa Caffarelli

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

Potential Role ◽

Noncoding Rnas ◽

Rna Metabolism ◽

Biological Processes ◽

Diagnostic Biomarkers ◽

Defective Rna ◽

Almost All ◽

Lateral Sclerosis

RNA metabolism is central to cellular physiopathology. Almost all the molecular pathways underpinning biological processes are affected by the events governing the RNA life cycle, ranging from transcription to degradation. The deregulation of these processes contributes to the onset and progression of human diseases. In recent decades, considerable efforts have been devoted to the characterization of noncoding RNAs (ncRNAs) and to the study of their role in the homeostasis of the nervous system (NS), where they are highly enriched. Acting as major regulators of gene expression, ncRNAs orchestrate all the steps of the differentiation programs, participate in the mechanisms underlying neural functions, and are crucially implicated in the development of neuronal pathologies, among which are neurodegenerative diseases. This review aims to explore the link between ncRNA dysregulation and amyotrophic lateral sclerosis (ALS), the most frequent motoneuron (MN) disorder in adults. Notably, defective RNA metabolism is known to be largely associated with this pathology, which is often regarded as an RNA disease. We also discuss the potential role that these transcripts may play as diagnostic biomarkers and therapeutic targets.

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