scholarly journals Epitranscriptomics of Mammalian Mitochondrial Ribosomal RNA

Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2181
Author(s):  
Ivan Laptev ◽  
Olga Dontsova ◽  
Petr Sergiev
Keyword(s):  
Ribosomal Rna ◽  
Functional Role ◽  
Evolutionary History ◽  
Assembly Process ◽  
Modified Nucleotides ◽  
Rna Molecules ◽  
Mitochondrial Ribosomes ◽  
Mitochondrial Rrna ◽  
Peptidyltransferase Center

Modified nucleotides are present in all ribosomal RNA molecules. Mitochondrial ribosomes are unique to have a set of methylated residues that includes universally conserved ones, those that could be found either in bacterial or in archaeal/eukaryotic cytosolic ribosomes and those that are present exclusively in mitochondria. A single pseudouridine within the mt-rRNA is located in the peptidyltransferase center at a position similar to that in bacteria. After recent completion of the list of enzymes responsible for the modification of mammalian mitochondrial rRNA it became possible to summarize an evolutionary history, functional role of mt-rRNA modification enzymes and an interplay of the mt-rRNA modification and mitoribosome assembly process, which is a goal of this review.

Organization of the nucleus, nucleolus, and protein-synthesizing apparatus in relation to cell development in roots of Pisum sativum

1975 ◽  
Vol 53 (2) ◽  
pp. 200-218 ◽  
Author(s):  
Nathalie M. Chaly ◽  
George Setterfield
Keyword(s):  
Ribosomal Rna ◽  
Functional Role ◽  
Cell Development ◽  
Nuclear Volume ◽  
Cell Maturation ◽  
Length Measurements ◽  
Rough Er ◽  
Nucleolar Size ◽  
Perichromatin Granules

For analysis, roots were divided into 10 1-mm segments starting at the tip. Root marking and cell-length measurements revealed three main developmental zones in the cortex: segment 1, cell division with compensating cell growth; segments 3–5, rapid cell elongation; segments 7–10, cell maturation without growth. Nuclear volume increased steadily to segment 5 and remained high. Chromatin was moderately condensed in segment 1, became quite decondensed in many nuclei of segment 3, and showed strongly condensed regions in about half of the maturing cells. Karyosomes, chromatin 'puffs,' and perichromatin granules were present in segments 1 and 3 but became much reduced as development proceeded. The nucleolus was large in segments 1 and 3 but was markedly smaller in segment 5 and beyond. As nucleolar size decreased the granular zone was reduced and chromatin within lacunae was withdrawn. Nucleoli of maturing cells were small compact fibrillar bodies. Nucleolar vacuoles were present in segment 1 but varied in size and frequency from root to root. The cytoplasm of segment 1 was packed with ribosomes and contained only isolated elements of endoplasmic reticulum (ER). By segment 3 extensive rough ER (RER) was present; this persisted through to segment 9, although becoming reduced in extent. Segments 3–7 showed the highest density of ribosomes on the ER. Ribosome number was decreased in the fully elongated cells. Incorporation of 3H-cytidine into ribosomal RNA was highest in segment 1 and declined steadily with development. The functional role of the described chromatin organizations is unresolved; the nucleolar and ribosomal changes seem characteristic of plant cell development and their significance is discussed.

scholarly journals N6-Methyladenosine Role in Cancer: Learning from AML

2018 ◽  
Author(s):  
Zaira Ianniello ◽  
Alessandro Fatica
Keyword(s):  
Functional Role ◽  
Cellular Differentiation ◽  
Normal Development ◽  
Cancer Development ◽  
Rna Modifications ◽  
Deep Impact ◽  
Rna Molecules ◽  
The World ◽  
Post Transcriptional Regulation

We are currently assisting at the explosion of the epitranscriptomics, which studies the functional role of chemical modifications into RNA molecules. Among more than 100 RNA modifications, the N6-methyladenosine (m6A), in particular, has attracted the interest of researchers all around the world. m6A is the most abundant internal chemical modification in mRNA and it can control any aspect of mRNA post-transcriptional regulation. m6A is installed by “writers”, removed by “erasers”, and recognized by “readers”, thus, it can be compared to the reversible and dynamic epigenetic modifications in histones and DNA. Given its fundamental role in determining the way mRNAs are expressed, it comes as no surprise that alterations to m6A modifications have a deep impact in cell differentiation, normal development and human diseases. Here, we review the proteins involved in m6A modification in mammals, m6A role in gene expression and its contribution to cancer development. In particular, we will focus on AML that, among first, has indicated how alteration in m6A modification can disrupt normal cellular differentiation and lead to cancer.

The functional role of ribosomal RNA in protein synthesis

Cell ◽  
1989 ◽  
Vol 57 (4) ◽  
pp. 525-529 ◽  
Author(s):  
Albert E. Dahlberg
Keyword(s):  
Protein Synthesis ◽  
Ribosomal Rna ◽  
Functional Role

Evolutionary shift toward protein-based architecture in trypanosomal mitochondrial ribosomes

Science ◽  
2018 ◽  
Vol 362 (6413) ◽  
pp. eaau7735 ◽  
Author(s):  
David J. F. Ramrath ◽  
Moritz Niemann ◽  
Marc Leibundgut ◽  
Philipp Bieri ◽  
Céline Prange ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Trypanosoma Brucei ◽  
Ribosomal Rna ◽  
Atomic Structure ◽  
Sleeping Sickness ◽  
Minimal Set ◽  
Functional Elements ◽  
Mitochondrial Ribosomes ◽  
Protein Components

Ribosomal RNA (rRNA) plays key functional and architectural roles in ribosomes. Using electron microscopy, we determined the atomic structure of a highly divergent ribosome found in mitochondria of Trypanosoma brucei, a unicellular parasite that causes sleeping sickness in humans. The trypanosomal mitoribosome features the smallest rRNAs and contains more proteins than all known ribosomes. The structure shows how the proteins have taken over the role of architectural scaffold from the rRNA: They form an autonomous outer shell that surrounds the entire particle and stabilizes and positions the functionally important regions of the rRNA. Our results also reveal the “minimal” set of conserved rRNA and protein components shared by all ribosomes that help us define the most essential functional elements.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

Expression and functional role of c-Kit and erbB2 in human hepatoblastoma.

2009 ◽  
Vol 221 (03) ◽  
Author(s):  
B Steiger ◽  
I Leuschner ◽  
D Denkhaus ◽  
D von Schweinitz ◽  
T Pietsch
Keyword(s):  
Functional Role
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