On the role of small peptides in the regulation of RNA synthesis in Tetrahymena pyriformis

1980 ◽  
Vol 45 (1) ◽  
pp. 31-39
Author(s):  
H.A. Andersen ◽  
A.E. Lykkesfeldt ◽  
S.J. Nielsen
Keyword(s):  
Ribosomal Rna ◽  
Rna Synthesis ◽  
Tetrahymena Pyriformis ◽  
Defined Medium ◽  
Specific Factor ◽  
Small Peptides ◽  
In Vitro Synthesis

Tetrahymena cells secrete a factor which inhibits RNA synthesis in vivo and in vitro. The factor is a relatively small peptide with a molecular weight between 300 and 1500 Daltons. Other, non-specific peptides in the broth medium or added to a chemically defined medium have a stimulatory effect on RNA synthesis in vivo and such peptides also stimulate the in vitro synthesis of RNA in a r-chromatin preparation. On the basis of these results we conclude that such extracellular small peptides compete with a specific factor which is part of the intracellular regulatory mechanism controlling the rate of RNA synthesis. The consequence of such competition is a high overproduction of ribosomal RNA in cells inoculated on peptide-rich broth media.

Ribonucleic acid synthesis inPlasmodium knowlesimaintained bothin vivoandin vitro

Parasitology ◽  
1975 ◽  
Vol 71 (2) ◽  
pp. 199-209 ◽  
Author(s):  
P. I. Trigg ◽  
P. G. Shakespeare ◽  
Susan J. Burt ◽  
Sally I. Kyd
Keyword(s):  
Ribosomal Rna ◽  
Rna Synthesis ◽  
Nuclear Division ◽  
Plasmodium Knowlesi ◽  
Acid Synthesis ◽  
Agarose Gel Electrophoresis ◽  
Trophozoite Stage ◽  
Late Trophozoite

RNA extracted from purified parasites ofPlasmodium knowlesiwas fractionated using agarose gel electrophoresis. Preparations from parasites grown bothin vivoandin vitrocontained species of RNA with sedimentation coefficients of 4·0S, 5·0S, 16·6S, 24·2S, 31·4S, 38·0S and 48·3S. There was less RNA present in parasites grownin vitrothan the equivalent stage parasites grownin vivobut the proportional amounts of the various species of RNA was similar in both cases. It is suggested that the 24·2S and 16·6S species of RNA are ribosomal and that the high molecular weight 31·4S, 38·0S and 48·0S species are ribosomal precursors. Ribosomal RNA synthesis occurs throughout the cell cycle during growth from the ring to the schizont stage; maximum incorporation of [H3]-adenosine occurs at the late trophozoite stage before nuclear division.

scholarly journals Mobility restriction in vivo of the heavy ribosomal subunit in a secretory cell.

1976 ◽  
Vol 70 (3) ◽  
pp. 573-580 ◽  
Author(s):  
U Lönn ◽  
J E Edström
Keyword(s):  
Endoplasmic Reticulum ◽  
Ribosomal Rna ◽  
Rna Synthesis ◽  
Ribosomal Subunit ◽  
Chironomus Tentans ◽  
Salivary Gland Cells ◽  
Unique Parameter ◽  
Labeled Rna

Analysis in insect (Chironomus tentans) salivary gland cells of labeled RNA as a function of time after precursor injection and its distance to the nuclear membrane, cytoplasmic zone analysis, could previously be used to demonstrate the presence of short-lasting gradients in newly labeled ribosomal RNA. Since the gradients were sensitive to puromycin, they are likely to be a result of diffusion restriction due to an engagement of the subunits into polysomes. In the present paper the possibility was explored of recording gradients that were caused by labeled subunits in puromycin-resistant associations, which, in all probability, involve the endoplasmic reticulum. It was found that labeled 28 S and 5 S RNA but not 18 S RNA were present in radioactivity gradients lasting for at least 2 days but less than 6 days. The gradients also remained during inhibition of RNA synthesis by actinomycin, and they were completely resistant to puromycin whether given in vivo or in vitro. The semipermanent gradients formed fhere offer a unique parameter for the in vivo study of conditions for formation and maintenance of heavy subunits in puromycin-resistant bonds. An explanation for these and previous results is that the light subunit, although restricted in movement by engagement to polysomes, is nevertheless free to exchange and spread between rounds of translation, whereas at least part of the heavy subunit population is bound to the endoplasmic reticulum and less free to spread. These results offer a good in vivo correlate to previous results on in vitro exchangeability of subunits.

Role of light in the in vivo and in vitro synthesis of spinach thioredoxin f

1992 ◽  
Vol 84 (2) ◽  
pp. 236-242 ◽  
Author(s):  
Jose L. Carrasco ◽  
Ana Chueca ◽  
Mariam Sahrawy ◽  
Rosario Hermoso ◽  
Juan J. Lazaro ◽  
...  
Keyword(s):  
In Vitro Synthesis ◽  
Role Of Light ◽  
Thioredoxin F

Role of light in the in vivo and in vitro synthesis of spinach thioredoxin f

1992 ◽  
Vol 84 (2) ◽  
pp. 236-242
Author(s):  
Jose L. Carrasco ◽  
Ana Chueca ◽  
Mariam Sahrawy ◽  
Rosario Hermoso ◽  
Juan J. Lazaro ◽  
...  
Keyword(s):  
In Vitro Synthesis ◽  
Role Of Light ◽  
Thioredoxin F

scholarly journals Three Ribosomal Operons of Escherichia coli Contain Genes Encoding Small RNAs That Interact With Hfq and CsrA in vitro

2021 ◽  
Vol 12 ◽  
Author(s):  
Thomas Søndergaard Stenum ◽  
Mette Kongstad ◽  
Erik Holmqvist ◽  
Birgitte Kallipolitis ◽  
Sine Lo Svenningsen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ribosomal Rna ◽  
Small Rnas ◽  
Genes Encoding ◽  
Ribosomal Operons ◽  
Dependent Processes ◽  
Fine Tune

Three out of the seven ribosomal RNA operons in Escherichia coli end in dual terminator structures. Between the two terminators of each operon is a short sequence that we report here to be an sRNA gene, transcribed as part of the ribosomal RNA primary transcript by read-through of the first terminator. The sRNA genes (rrA, rrB and rrF) from the three operons (rrnA, rrnB and rrnD) are more than 98% identical, and pull-down experiments show that their transcripts interact with Hfq and CsrA. Deletion of rrA, B, F, as well as overexpression of rrB, only modestly affect known CsrA-regulated phenotypes like biofilm formation, pgaA translation and glgC translation, and the role of the sRNAs in vivo may not yet be fully understood. Since RrA, B, F are short-lived and transcribed along with the ribosomal RNA components, their concentration reflect growth-rate regulation at the ribosomal RNA promoters and they could function to fine-tune other growth-phase-dependent processes in the cell. The primary and secondary structure of these small RNAs are conserved among species belonging to different genera of Enterobacteriales.

Inhibition of rRNA synthesis following incorporation of 5-bromodeoxyuridine into DNA of Tetrahymena pyriformis

1975 ◽  
Vol 17 (3) ◽  
pp. 495-502
Author(s):  
A.E. Lykkesfeldt ◽  
H.A. Andersen
Keyword(s):  
Dna Replication ◽  
Ribosomal Rna ◽  
Rna Synthesis ◽  
Nuclear Dna ◽  
Tetrahymena Pyriformis ◽  
Growth Conditions ◽  
Defined Medium ◽  
Rrna Synthesis ◽  
Chemically Defined Medium ◽  
Dividing Cells

Tetrahymena pyriformis was grown on chemically defined medium in the presence of 5-bromodeoxyuridine (BUdR). Under these growth conditions more than 60% of the thymidine sites in DNA were substituted with BUdR. It was found that RNA synthesis was strongly inhibited by the presence of BUdR in DNA. To assure that incorporation of BUdR into DNA was a prerequisite of the effect observed, BUdR was added to synchronously dividing cells. BUdR had no effect on the cells when present outside the period of nuclear DNA replication, whereas RNA synthesis was strongly inhibited as soon as the genes coding for ribosomal RNA had replicated in the presence of BUdR.

Synthesis of ribosomal RNA on a protein-DNA complex isolated from bacteria: A comparison of ribosomal RNA synthesis in vitro and in vivo

1970 ◽  
Vol 52 (2) ◽  
pp. 281-300 ◽  
Author(s):  
David E. Pettijohn ◽  
Kathleen Clarkson ◽  
Charles R. Kossman ◽  
O.Gordon Stonington
Keyword(s):  
Ribosomal Rna ◽  
Rna Synthesis ◽  
Dna Complex

Nuclear p26, a small heat shock/α-crystallin protein, and its relationship to stress resistance in Artemia franciscana embryos

2001 ◽  
Vol 204 (13) ◽  
pp. 2339-2350 ◽  
Author(s):  
Julia K. Willsie ◽  
James S. Clegg
Keyword(s):  
Heat Shock ◽  
Rna Synthesis ◽  
Low Ph ◽  
Artemia Franciscana ◽  
Precursor Pool ◽  
In Vivo Experiments ◽  
Nuclear Targets

SUMMARY The role of the small heat shock/α-crystallin protein, p26, in transcription in Artemia franciscana embryos was examined using isolated nuclei, containing either control or elevated levels of p26, in transcription run-on assays. Heat shock or anoxia in vivo and acid pH in vitro were used to transfer p26 into nuclei. The results suggest that parameters other than, or in addition to, p26 are responsible for the reduced transcription rates observed and that decreases in pHi are involved. In vivo experiments indicate that RNA synthesis and, to a lesser extent, protein synthesis are downregulated in intact embryos recovering from heat shock and that the precursor pool is not limiting. Confocal microscopy confirmed that p26 moves into nuclei in response to heat shock and anoxia in vivo, and to low pH in vitro, and indicated that the nuclear distribution of p26 is similar under all three conditions. We present evidence that unstressed (control) embryos containing p26 in all their nuclei will not hatch, even under permissive conditions, and propose that they are unable to terminate diapause. Potential nuclear targets of p26 chaperone activity are discussed.

scholarly journals The Role of Mitochondria-Derived Peptides in Cardiovascular Diseases and Their Potential as Therapeutic Targets

2021 ◽  
Vol 22 (16) ◽  
pp. 8770
Author(s):  
Siarhei A. Dabravolski ◽  
Nikita G. Nikiforov ◽  
Antonina V. Starodubova ◽  
Tatyana V. Popkova ◽  
Alexander N. Orekhov
Keyword(s):  
Cardiovascular Diseases ◽  
Therapeutic Targets ◽  
Oxygen Species ◽  
Small Peptides ◽  
Therapeutic Application ◽  
Novel Biomarkers ◽  
And Oxidative Stress

Mitochondria-derived peptides (MDPs) are small peptides hidden in the mitochondrial DNA, maintaining mitochondrial function and protecting cells under different stresses. Currently, three types of MDPs have been identified: Humanin, MOTS-c and SHLP1-6. MDPs have demonstrated anti-apoptotic and anti-inflammatory activities, reactive oxygen species and oxidative stress-protecting properties both in vitro and in vivo. Recent research suggests that MDPs have a significant cardioprotective role, affecting CVDs (cardiovascular diseases) development and progression. CVDs are the leading cause of death globally; this term combines disorders of the blood vessels and heart. In this review, we focus on the recent progress in understanding the relationships between MDPs and the main cardiovascular risk factors (atherosclerosis, insulin resistance, hyperlipidaemia and ageing). We also will discuss the therapeutic application of MDPs, modified and synthetic MDPs, and their potential as novel biomarkers and therapeutic targets.

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