scholarly journals From differential transcription of ribosomal proteins to differential structure of ribosomes

2015 ◽  
Author(s):  
Nikolai Slavov
Keyword(s):  
Growth Rate ◽  
Protein Synthesis ◽  
Cell Growth ◽  
Ribosomal Proteins ◽  
Structure And Function ◽  
Mrna Levels ◽  
Cell Growth Rate ◽  
Direct Data ◽  
And Function ◽  
Differential Transcription

About a decade ago, I observed that as the cell growth rate increases, mRNAs coding for ribosomal proteins are transcriptionally induced to varying degrees. This observation puzzled me as it defied my expectation that faster growing cells meet their demands for increased protein synthesis by simply inducing all ribosomal proteins to the same degree to make more ribosomes. These initial data were limited to mRNA levels and thus too indirect to make concrete conclusions about ribosomal structure and function. This commentary outlines my trajectory investigating this puzzle in search of more direct data.

scholarly journals From differential transcription of ribosomal proteins to differential structure of ribosomes

2015 ◽  
Author(s):  
Nikolai Slavov
Keyword(s):  
Growth Rate ◽  
Protein Synthesis ◽  
Cell Growth ◽  
Ribosomal Proteins ◽  
Structure And Function ◽  
Mrna Levels ◽  
Cell Growth Rate ◽  
Direct Data ◽  
And Function ◽  
Differential Transcription

About a decade ago, I observed that as the cell growth rate increases, mRNAs coding for ribosomal proteins are transcriptionally induced to varying degrees. This observation puzzled me as it defied my expectation that faster growing cells meet their demands for increased protein synthesis by simply inducing all ribosomal proteins to the same degree to make more ribosomes. These initial data were limited to mRNA levels and thus too indirect to make concrete conclusions about ribosomal structure and function. This commentary outlines my trajectory investigating this puzzle in search of more direct data.

scholarly journals ANTAGONISM BY DIBUTYRYL ADENOSINE CYCLIC 3',5'-MONOPHOSPHATE AND TESTOSTERONE OF CELL ROUNDING REACTIONS

1973 ◽  
Vol 59 (2) ◽  
pp. 471-479 ◽  
Author(s):  
Brian Storrie
Keyword(s):  
Growth Rate ◽  
Protein Synthesis ◽  
Cell Growth ◽  
Concanavalin A ◽  
Divalent Cations ◽  
Cell Growth Rate ◽  
Dibutyryl Camp ◽  
Cell Rounding ◽  
Drug Removal ◽  
Kinetics Of

In an attempt to understand further the mechanism of the morphological and functional "reverse transformation" of CHO-K1 cells induced by dibutyryl adenosine cyclic 3',5'-monophosphate (cAMP) and testosterone, the kinetics of variation in the susceptibility of cells to rounding after the addition or deletion of dibutyryl cAMP and testosterone have been investigated. Changes in susceptibility to cell rounding upon removal of divalent cations or pulse exposure to concanavalin A were complete within 0.5–1 h after addition or deletion of drug. In comparison, the gross conversion of CHO-K1 cells from epithelial- to fibroblast-like morphology after drug treatment or the converse change after drug removal required 8 or 4 h, respectively. The effects on cell rounding are not caused by an effect of dibutyryl cAMP upon cell growth rate. Inhibitor experiments indicate that the changes investigated do not require continued RNA or protein synthesis and are not prevented by agents which depolymerize microtubules.

scholarly journals The Correlation Between Cell and Nucleus Size is Explained by an Eukaryotic Cell Growth Model

2021 ◽  
Author(s):  
Yufei Wu ◽  
Paul Janmey ◽  
Sean X. Sun
Keyword(s):  
Growth Rate ◽  
Cell Growth ◽  
Cell Volume ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Eukaryotic Cell ◽  
Nuclear Volume ◽  
Strongly Correlated ◽  
Cell Growth Rate ◽  
A Cell

In eukaryotes, the cell volume is observed to be strongly correlated with the nuclear volume. The slope of this correlation depends on the cell type, growth condition, and the physical environment of the cell. We develop a computational model of cell growth and proteome increase, incorporating the kinetics of amino acid import, protein/ribosome synthesis and degradation, and active transport of proteins between the cytoplasm and the nucleoplasm. We also include a simple model of ribosome biogenesis and assembly. Results show that the cell volume is tightly correlated with the nuclear volume, and the cytoplasm-nucleoplasm transport rates strongly influences the cell growth rate as well as the cytoplasm/nucleoplasm ratio. Ribosome assembly and the ratio of ribosomal proteins to mature ribosomes also influence the cell volume and the cell growth rate. We find that in order to regulate the cell growth rate and the cytoplasm/nucleoplasm ratio, the cell must optimally control groups of kinetic parameters together, which could explain the quantitative roles of canonical growth pathways. Finally, using an extension of our model and single cell RNAseq data, it is possible to construct a detailed proteome distribution, provided that a cell division mechanism is known.

82 Methyl Donor Supplementation Alters Cytosine Methylation and Biological Processes of Cells Cultured in Divergent Glucose Media Reflecting Improvements in Mitochondrial Respiration and Cell Growth Rate

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 109-109
Author(s):  
Matthew S Crouse ◽  
Wellison Jarles Da Silva Diniz ◽  
Joel Caton ◽  
Carl R Dahlen ◽  
Lawrence P Reynolds ◽  
...  
Keyword(s):  
Growth Rate ◽  
Cell Proliferation ◽  
Cell Growth ◽  
Vitamin B12 ◽  
Mitochondrial Respiration ◽  
Cytosine Methylation ◽  
Biological Processes ◽  
Cell Growth Rate ◽  
Metabolic Processes ◽  
Positive Regulation

Abstract We hypothesized that supplementation of one-carbon metabolites (OCM: methionine, folate, choline, and vitamin B12) to bovine embryonic tracheal fibroblasts in divergent glucose media would alter cytosine methylation, and alterations in cytosine methylation will reflect biological processes matching previously improved mitochondrial respiration, cell proliferation, and cell growth rate data. Cells were cultured with 1g/L glucose (Low) or 4.5g/L glucose (High). Control medium (CON) contained basal concentrations of folate (0.001g/L), choline (0.001g/L), vitamin B12 (4µg/L), and methionine (0.015g/L). The OCM were supplemented at 2.5 and 5 times (2.5X and 5X, respectively) the CON media, except methionine was limited to 2X across all supplemented treatments. Cells were passaged three times in their treatment media before DNA extraction. Reduced representation bisulfite sequencing was adopted to analyze and compare the genomic methylation patterns within and across treatments using edgeR. Biological processes (BP) were retrieved based on the nearest genes of differentially methylated cytosines (P < 0.01) for each comparison between treatments. In both Low and High treatments, greater OCM increased the proportion of hypomethylated vs. hypermethylated cytosines. Functional analyses pointed out positive regulation of BP related to energy metabolism, except for the contrasts within the High group. Among the BP, we can highlight positive regulation of: GTPase activity, catalytic activity, molecular function, protein modification processes, phosphorylation, protein phosphorylation, cellular protein metabolic processes, MAPK cascade, and metabolic processes. These data support previously reported results from this experiment that showed increased mitochondrial respiration, cell proliferation, and growth rates with increasing OCM levels. We interpret these data to imply that when energy and OCM requirements are met for growth and basal methylation levels, DNA methylation levels decrease which may allow for greater transcription. Thus, OCM can be utilized for other functions such as polyamine synthesis, nucleotide synthesis, energetic metabolites, and phosphatidylcholine synthesis. USDA is an equal opportunity provider and employer.

PGE2 inhibition & interferon-gamma restoration of type 1 T cell growth rate in atopic dermatitis

1993 ◽  
Vol 6 (1) ◽  
pp. 27
Author(s):  
Sai C. Chan ◽  
Shi-Hua Li ◽  
William R. Henderson ◽  
Jon M. Hanifin
Keyword(s):  
Growth Rate ◽  
Atopic Dermatitis ◽  
T Cell ◽  
Cell Growth ◽  
Interferon Gamma ◽  
Cell Growth Rate ◽  
T Cell Growth

scholarly journals Differences in size, structure and function of free and membrane-bound polyribosomes of rat liver. Evidence for a single class of membrane-bound polyribosomes

1977 ◽  
Vol 168 (1) ◽  
pp. 1-8 ◽  
Author(s):  
J C Ramsey ◽  
W J Steele
Keyword(s):  
Protein Synthesis ◽  
Rat Liver ◽  
Size Structure ◽  
Large Fraction ◽  
Liver Homogenate ◽  
Structure And Function ◽  
Structural And Functional Properties ◽  
Membrane Bound ◽  
And Function

Free loosely bound and tightly bound polyribosomes were separated from rat liver homogenate by salt extraction followed by differential centrifugation, and several of their structural and functional properties were compared to resolve the existence of loosely bound polyribosomes and verify the specificity of the separation. The free and loosely bound polyribosomes have similar sedimentation profiles and polyribosome contents, their subunit proteins have similar electrophoretic patterns and their products of protein synthesis in vitro show a close correspondence in size and amounts synthesized. In contrast, the tightly bound polyribosomes have different properties from those of the free and loosely bound polyribosomes; their average size is significantly smaller; their polyribosome content is higher; their 60 S-subunit proteins lack two components and contain four or more components not found elsewhere; their products of protein synthesis in vitro differ in size and amounts synthesized. These observations show that rat liver membranes entrap a large fraction of the free polyribosomes at low salt concentrations and that these polyribosomes are similar to those of the free-polyribosome fraction and are different from those of the tightly bound polyribosome fraction in size, structure and function.

scholarly journals Tagging of RPS9 as a tool for ribosome purification and identification of ribosome-associated proteins

2020 ◽  
pp. 57-57
Author(s):  
Bogdan Jovanovic ◽  
Lisa Schubert ◽  
Fabian Poetz ◽  
Georg Stoecklin
Keyword(s):  
Protein Synthesis ◽  
Ribosomal Proteins ◽  
Associated Factors ◽  
Ribosomal Subunit ◽  
High Specificity ◽  
Negative Control ◽  
Tev Protease ◽  
Protease Cleavage ◽  
Associated Proteins ◽  
And Function

Ribosomes, the catalytic machinery required for protein synthesis, are comprised of 4 ribosomal RNAs and about 80 ribosomal proteins in mammals. Ribosomes further interact with numerous associated factors that regulate their biogenesis and function. As mutations of ribosomal proteins and ribosome associated proteins cause many diseases, it is important to develop tools by which ribosomes can be purified efficiently and with high specificity. Here, we designed a method to purify ribosomes from human cell lines by C-terminally tagging human RPS9, a protein of the small ribosomal subunit. The tag consists of a flag peptide and a streptavidin-binding peptide (SBP) separated by the tobacco etch virus (TEV) protease cleavage site. We demonstrate that RPS9-Flag-TEV-SBP (FTS) is efficiently incorporated into the ribosome without interfering with regular protein synthesis. Using HeLa-GFP-G3BP1 cells stably expressing RPS9-FTS or, as a negative control, mCherry-FTS, we show that complete ribosomes as well as numerous ribosome-associated proteins are efficiently and specifically purified following pull-down of RPS9-FTS using streptavidin beads. This tool will be helpful for the characterization of human ribosome heterogeneity, post-translational modifications of ribosomal proteins, and changes in ribosome-associated factors after exposing human cells to different stimuli and conditions.

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