scholarly journals Integrating Wheat Nucleolus Structure and Function: Variation in the Wheat Ribosomal RNA and Protein Genes

2021 ◽  
Vol 12 ◽  
Author(s):  
Rudi Appels ◽  
Penghao Wang ◽  
Shahidul Islam

We review the coordinated production and integration of the RNA (ribosomal RNA, rRNA) and protein (ribosomal protein, RP) components of wheat cytoplasmic ribosomes in response to changes in genetic constitution, biotic and abiotic stresses. The components examined are highly conserved and identified with reference to model systems such as human, Arabidopsis, and rice, but have sufficient levels of differences in their DNA and amino acid sequences to form fingerprints or gene haplotypes that provide new markers to associate with phenotype variation. Specifically, it is argued that populations of ribosomes within a cell can comprise distinct complements of rRNA and RPs to form units with unique functionalities. The unique functionalities of ribosome populations within a cell can become central in situations of stress where they may preferentially translate mRNAs coding for proteins better suited to contributing to survival of the cell. In model systems where this concept has been developed, the engagement of initiation factors and elongation factors to account for variation in the translation machinery of the cell in response to stresses provided the precedents. The polyploid nature of wheat adds extra variation at each step of the synthesis and assembly of the rRNAs and RPs which can, as a result, potentially enhance its response to changing environments and disease threats.

2020 ◽  
Vol 16 (34) ◽  
pp. 2853-2861
Author(s):  
Yanli Li ◽  
Rui Yang ◽  
Limo Chen ◽  
Sufang Wu

CD38 is a transmembrane glycoprotein that is widely expressed in a variety of human tissues and cells, especially those in the immune system. CD38 protein was previously considered as a cell activation marker, and today monoclonal antibodies targeting CD38 have witnessed great achievements in multiple myeloma and promoted researchers to conduct research on other tumors. In this review, we provide a wide-ranging review of the biology and function of the human molecule outside the field of myeloma. We focus mainly on current research findings to summarize and update the findings gathered from diverse areas of study. Based on these findings, we attempt to extend the role of CD38 in the context of therapy of solid tumors and expand the role of the molecule from a simple marker to an immunomodulator.


Author(s):  
Vitalii Kryvenko ◽  
Olga Vagin ◽  
Laura A. Dada ◽  
Jacob I. Sznajder ◽  
István Vadász

Abstract The Na,K-ATPase establishes the electrochemical gradient of cells by driving an active exchange of Na+ and K+ ions while consuming ATP. The minimal functional transporter consists of a catalytic α-subunit and a β-subunit with chaperon activity. The Na,K-ATPase also functions as a cell adhesion molecule and participates in various intracellular signaling pathways. The maturation and trafficking of the Na,K-ATPase include co- and post-translational processing of the enzyme in the endoplasmic reticulum (ER) and the Golgi apparatus and subsequent delivery to the plasma membrane (PM). The ER folding of the enzyme is considered as the rate-limiting step in the membrane delivery of the protein. It has been demonstrated that only assembled Na,K-ATPase α:β-complexes may exit the organelle, whereas unassembled, misfolded or unfolded subunits are retained in the ER and are subsequently degraded. Loss of function of the Na,K-ATPase has been associated with lung, heart, kidney and neurological disorders. Recently, it has been shown that ER dysfunction, in particular, alterations in the homeostasis of the organelle, as well as impaired ER-resident chaperone activity may impede folding of Na,K-ATPase subunits, thus decreasing the abundance and function of the enzyme at the PM. Here, we summarize our current understanding on maturation and subsequent processing of the Na,K-ATPase in the ER under physiological and pathophysiological conditions. Graphic Abstract


2021 ◽  
Vol 7 (2) ◽  
pp. 30
Author(s):  
Laeya Baldini ◽  
Bruno Charpentier ◽  
Stéphane Labialle

Box C/D small nucleolar RNAs (C/D snoRNAs) represent an ancient family of small non-coding RNAs that are classically viewed as housekeeping guides for the 2′-O-methylation of ribosomal RNA in Archaea and Eukaryotes. However, an extensive set of studies now argues that they are involved in mechanisms that go well beyond this function. Here, we present these pieces of evidence in light of the current comprehension of the molecular mechanisms that control C/D snoRNA expression and function. From this inventory emerges that an accurate description of these activities at a molecular level is required to let the snoRNA field enter in a second age of maturity.


2021 ◽  
Vol 22 (2) ◽  
pp. 947
Author(s):  
Mitsuki Tsuruta ◽  
Yui Sugitani ◽  
Naoki Sugimoto ◽  
Daisuke Miyoshi

Methylated cytosine within CpG dinucleotides is a key factor for epigenetic gene regulation. It has been revealed that methylated cytosine decreases DNA backbone flexibility and increases the thermal stability of DNA. Although the molecular environment is an important factor for the structure, thermodynamics, and function of biomolecules, there are few reports on the effects of methylated cytosine under a cell-mimicking molecular environment. Here, we systematically investigated the effects of methylated cytosine on the thermodynamics of DNA duplexes under molecular crowding conditions, which is a critical difference between the molecular environment in cells and test tubes. Thermodynamic parameters quantitatively demonstrated that the methylation effect and molecular crowding effect on DNA duplexes are independent and additive, in which the degree of the stabilization is the sum of the methylation effect and molecular crowding effect. Furthermore, the effects of methylation and molecular crowding correlate with the hydration states of DNA duplexes. The stabilization effect of methylation was due to the favorable enthalpic contribution, suggesting that direct interactions of the methyl group with adjacent bases and adjacent methyl groups play a role in determining the flexibility and thermodynamics of DNA duplexes. These results are useful to predict the properties of DNA duplexes with methylation in cell-mimicking conditions.


1985 ◽  
Vol 8 (3-4) ◽  
pp. 747-755 ◽  
Author(s):  
Harry F. Noller ◽  
Barbara J. Van Stolk ◽  
Danesh Moazed ◽  
Stephen Douthwaite ◽  
Robin R. Gutell

2007 ◽  
Vol 177 (6) ◽  
pp. 981-993 ◽  
Author(s):  
Anton Khmelinskii ◽  
Clare Lawrence ◽  
Johanna Roostalu ◽  
Elmar Schiebel

Spindle elongation in anaphase of mitosis is a cell cycle–regulated process that requires coordination between polymerization, cross-linking, and sliding of microtubules (MTs). Proteins that assemble at the spindle midzone may be important for this process. In this study, we show that Ase1 and the separase–Slk19 complex drive midzone assembly in yeast. Whereas the conserved MT-bundling protein Ase1 establishes a midzone, separase–Slk19 is required to focus and center midzone components. An important step leading to spindle midzone assembly is the dephosphorylation of Ase1 by the protein phosphatase Cdc14 at the beginning of anaphase. Failure to dephosphorylate Ase1 delocalizes midzone proteins and delays the second, slower phase of anaphase B. In contrast, in cells expressing nonphosphorylated Ase1, anaphase spindle extension is faster, and spindles frequently break. Cdc14 also controls the separase–Slk19 complex indirectly via the Aurora B kinase. Thus, Cdc14 regulates spindle midzone assembly and function directly through Ase1 and indirectly via the separase–Slk19 complex.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Ranjith K. Papareddy ◽  
Katalin Páldi ◽  
Subramanian Paulraj ◽  
Ping Kao ◽  
Stefan Lutzmayer ◽  
...  

Abstract Background Eukaryotic genomes are partitioned into euchromatic and heterochromatic domains to regulate gene expression and other fundamental cellular processes. However, chromatin is dynamic during growth and development and must be properly re-established after its decondensation. Small interfering RNAs (siRNAs) promote heterochromatin formation, but little is known about how chromatin regulates siRNA expression. Results We demonstrate that thousands of transposable elements (TEs) produce exceptionally high levels of siRNAs in Arabidopsis thaliana embryos. TEs generate siRNAs throughout embryogenesis according to two distinct patterns depending on whether they are located in euchromatic or heterochromatic regions of the genome. siRNA precursors are transcribed in embryos, and siRNAs are required to direct the re-establishment of DNA methylation on TEs from which they are derived in the new generation. Decondensed chromatin also permits the production of 24-nt siRNAs from heterochromatic TEs during post-embryogenesis, and siRNA production from bipartite-classified TEs is controlled by their chromatin states. Conclusions Decondensation of heterochromatin in response to developmental, and perhaps environmental, cues promotes the transcription and function of siRNAs in plants. Our results indicate that chromatin-mediated siRNA transcription provides a cell-autonomous homeostatic control mechanism to help reconstitute pre-existing chromatin states during growth and development including those that ensure silencing of TEs in the future germ line.


1985 ◽  
Vol 4 (13B) ◽  
pp. 3879-3886 ◽  
Author(s):  
Y. Mishima ◽  
T. Mitsuma ◽  
K. Ogata

2020 ◽  
Author(s):  
Sebastien Riquier ◽  
Marc Mathieu ◽  
Anthony Boureux ◽  
Florence Ruffle ◽  
Jean-Marc Lemaitre ◽  
...  

AbstractThe development of RNA sequencing (RNAseq) and corresponding emergence of public datasets have created new avenues of transcriptional marker search. The long non-coding RNAs (lncRNAs) constitute an emerging class of transcripts with a potential for high tissue specificity and function. Using a dedicated bioinformatics pipeline, we propose to construct a cell-specific catalogue of unannotated lncRNAs and to identify the strongest cell markers. This pipeline uses ab initio transcript identification, pseudoalignment and new methodologies such as a specific k-mer approach for naive quantification of expression in numerous RNAseq data.For an application model, we focused on Mesenchymal Stem Cells (MSCs), a type of adult multipotent stem-cells of diverse tissue origins. Frequently used in clinics, these cells lack extensive characterisation. Our pipeline was able to highlight different lncRNAs with high specificity for MSCs. In silico methodologies for functional prediction demonstrated that each candidate represents one specific state of MSCs biology. Together, these results suggest an approach that can be employed to harness lncRNA as cell marker, showing different candidates as potential actors in MSCs biology, while suggesting promising directions for future experimental investigations.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3160 ◽  
Author(s):  
Kumar Manochitra ◽  
Subhash Chandra Parija

BackgroundAmoebiasis is the third most common parasitic cause of morbidity and mortality, particularly in countries with poor hygienic settings. There exists an ambiguity in the diagnosis of amoebiasis, and hence there arises a necessity for a better diagnostic approach. Serine-richEntamoeba histolyticaprotein (SREHP), peroxiredoxin and Gal/GalNAc lectin are pivotal inE. histolyticavirulence and are extensively studied as diagnostic and vaccine targets. For elucidating the cellular function of these proteins, details regarding their respective quaternary structures are essential. However, studies in this aspect are scant. Hence, this study was carried out to predict the structure of these target proteins and characterize them structurally as well as functionally using appropriatein-silicomethods.MethodsThe amino acid sequences of the proteins were retrieved from National Centre for Biotechnology Information database and aligned using ClustalW. Bioinformatic tools were employed in the secondary structure and tertiary structure prediction. The predicted structure was validated, and final refinement was carried out.ResultsThe protein structures predicted by i-TASSER were found to be more accurate than Phyre2 based on the validation using SAVES server. The prediction suggests SREHP to be an extracellular protein, peroxiredoxin a peripheral membrane protein while Gal/GalNAc lectin was found to be a cell-wall protein. Signal peptides were found in the amino-acid sequences of SREHP and Gal/GalNAc lectin, whereas they were not present in the peroxiredoxin sequence. Gal/GalNAc lectin showed better antigenicity than the other two proteins studied. All the three proteins exhibited similarity in their structures and were mostly composed of loops.DiscussionThe structures of SREHP and peroxiredoxin were predicted successfully, while the structure of Gal/GalNAc lectin could not be predicted as it was a complex protein composed of sub-units. Also, this protein showed less similarity with the available structural homologs. The quaternary structures of SREHP and peroxiredoxin predicted from this study would provide better structural and functional insights into these proteins and may aid in development of newer diagnostic assays or enhancement of the available treatment modalities.


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