Gibberellic acid-stimulated and auxin-stimulated cell growth in relation to RNA synthesis, protein synthesis and development in the wheat coleoptile

1982 ◽  
Vol 55 (3) ◽  
pp. 395-401 ◽  
Author(s):  
R. J. Rose ◽  
J. B. Crossman
Keyword(s):  
Protein Synthesis ◽  
Cell Growth ◽  
Gibberellic Acid ◽  
Rna Synthesis ◽  
Wheat Coleoptile

Wachstumsparameter in normalen und durch Actinomycin verlängerten Zellzyklen von Tetrahymena / Growth Parameters in Normal and Actinomycin-induced prolonged Cell Cycles of Tetrahymena

1969 ◽  
Vol 24 (12) ◽  
pp. 1624-1629 ◽  
Author(s):  
Günter Cleffmann
Keyword(s):  
Cell Cycle ◽  
Protein Synthesis ◽  
Cell Division ◽  
Dna Replication ◽  
Cell Growth ◽  
Rna Synthesis ◽  
Growth Parameters ◽  
Average Duration ◽  
Cell Cycles ◽  
Growing Cell

Actinomycin in low concentration (0,2 μg/ml — 0,5 μg/ml) prolongs the average duration of the cell cycle of Tetrahymena considerably, but does not inhibit cell division completely. Some parameters of the growing cell have been tested in cell cycles extended in this way and compared to those of normally growing cells. The RNA synthesis of treated cells is reduced to such an extent that the RNA content per cell decreases during the prolonged cell cycle. Nevertheless cell growth, protein synthesis and DNA replication proceed at almost the same rate as in untreated cells. These findings indicate that the presence of actinomycin does not interfere with RNA fractions necessary for growth but reduce the synthesis of RNA fractions which are essential for cell division. Therefore a longer period is needed for their accumulation.

FEMALE ENDOCRINE CONTROL MECHANISMS DURING THE NEONATAL PERIOD

1972 ◽  
Vol 70 (2) ◽  
pp. 396-408 ◽  
Author(s):  
K.-D. Schulz ◽  
H. Haarmann ◽  
A. Harland
Keyword(s):  
Protein Synthesis ◽  
Reproductive System ◽  
Rna Synthesis ◽  
Neonatal Period ◽  
High Dose ◽  
Female Reproductive System ◽  
Endocrine Control ◽  
Hypothalamic Region ◽  
Rna And Protein Synthesis ◽  
Physiological Dose

ABSTRACT The present investigation deals with the oestrogen-sensitivity of the female reproductive system during the neonatal period. Newborn female guinea pigs were used as test animals. At different times after a single subcutaneous injection of a physiological dose of 0.1 μg or an unphysiologically high dose of 10 μg 17β-oestradiol/100 g body weight, the RNA- and protein-synthesis was examined in the hypothalamic region, pituitary, cerebral cortex, liver, adrenal gland, ovary and uterus. With a physiological dose an increase in organ weight, protein content, RNA-and protein-synthesis was found only in the uterus. These alterations turned out to be dose-dependent. In addition to the findings in the uterus an inhibition of the aminoacid incorporation rate occurred in the liver following the injection of the high oestradiol dose. As early as 1 hour after the administration of 0.1 μg 17β-oestradiol an almost 100% increase in uterine protein synthesis was detectable. This result demonstrates a high oestrogen-sensitivity of this organ during the neonatal period. All the other organs of the female reproductive system such as the hypothalamus, pituitary and ovary did not show any oestrogen response. Therefore the functional immaturity of the uterus during post partem life is not the result of a deficient hormone sensitivity but is correlated with the absence of a sufficient hormonal stimulus at this time. The investigation on the effects of actinomycin resulted in different reactions in the uterus and liver. In contrast to the liver a paradoxical actinomycin effect was found in the uterus after treatment with actinomycin alone. This effect is characterized by a small inhibition of RNA-synthesis and a 50% increase in protein synthesis. The treatment of the newborn test animals with actinomycin and 17β-oestradiol together abolished the oestrogen-induced stimulation of the uterine RNA-and protein-synthesis. Consequently, the effect of oestrogens during the neonatal period is also connected with the formation of new proteins via an increased DNA-directed RNA-synthesis.

Ca2+ dynamics of thrombin-stimulated rat heart-derived embryonic myocytes: relationship to protein synthesis and cell growth

2003 ◽  
Vol 35 (11) ◽  
pp. 1573-1587 ◽  
Author(s):  
Margaret A. Brostrom ◽  
Zui Pan ◽  
Sally Meiners ◽  
Christopher Drumm ◽  
Ijaz Ahmed ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Cell Growth ◽  
Rat Heart

RNA synthesis in the embryo suspensor ofPhaseolus coccineus at two stages of embryogenesis, and the effect of supplied gibberellic acid

PROTOPLASMA ◽  
1992 ◽  
Vol 167 (3-4) ◽  
pp. 152-158 ◽  
Author(s):  
L. M. C. Forino ◽  
A. M. Tagliasacchi ◽  
A. Cavallini ◽  
G. Cionini ◽  
E. Giraldi ◽  
...  
Keyword(s):  
Gibberellic Acid ◽  
Rna Synthesis ◽  
Embryo Suspensor ◽  
Two Stages

scholarly journals Onset of ribosome degradation during cessation of growth in BHK-21/C13 cells

1978 ◽  
Vol 176 (3) ◽  
pp. 933-941 ◽  
Author(s):  
W T Melvin ◽  
H M Keir
Keyword(s):  
Cell Growth ◽  
Dna Synthesis ◽  
Protein Content ◽  
Rna Synthesis ◽  
Step Down ◽  
Rrna Degradation ◽  
Synthesis And Degradation

When BHK-21/C13 cells growing exponentially in 10% serum are transferred to a medium containing only 0.25% serum, cell growth is decreased. After initial changes in RNA synthesis and degradation, protein content of the cultures reaches a plateau and eventually DNA synthesis is arrested. rRNA is relatively stable in exponentially growing cells. Immediately after ‘step-down’ rRNA degradation commences, but poly(A)-containing RNA does not appear to be degraded any faster than in control cells. Reutilization of RNA precursors has been independently measured and amounts to less than 1%/h for rRNA, insufficient to influence the conclusion that rRNA degradation begins almost immediately after ‘step-down’. The degree of reutilization of uridine is much greater for poly(A)-containing RNA than for poly(A)-free RNA.

The Effect of Insulin on the Growth and Metabolism of the Human Diploid Cell, Wi-38

1970 ◽  
Vol 7 (2) ◽  
pp. 575-585
Author(s):  
J. B. GRIFFITHS
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Glucose Uptake ◽  
Rna Synthesis ◽  
Cultured Cells ◽  
Cell Sheet ◽  
High Energy ◽  
Contact Inhibition ◽  
Contributory Factor ◽  
Membrane Area

In a confluent culture of WI-38 cells the membrane area available for nutrient uptake is greatly reduced and the possibility exists that this reduction in uptake capacity of the cell is a contributory factor in contact inhibition. Insulin has been reported by many authors to facilitate glucose uptake and also to stimulate protein, DNA and RNA synthesis, glycolysis, pino-cytosis and growth in cultured cells. The effect of insulin on WI-38 cells was determined, therefore, to find out whether it enabled the cell to escape from contact inhibition of growth. The action of insulin was found to be dependent upon medium composition. Growth and protein synthesis were stimulated in Eagle's minimal essential medium, but not when this medium was supplemented with glucose and glutamine. Apparently insulin is only effective when high-energy compounds become limiting. Whilst insulin did not induce any post-confluent division, the protein content of cells was increased by 30%, and this was correlated with an increased rate of protein synthesis. Despite this increased activity in protein metabolism, the utilization of amino acids was less in the presence of insulin indicating that a control mechanism for more economical utilization of amino acids for protein synthesis was activated by insulin. Insulin had no effect on RNA synthesis, and only a slight inhibitory effect on DNA synthesis. Evidence was produced suggesting that insulin blocked cell division and encouraged differentiation. Glucose uptake and incorporation into the cell was stimulated by insulin, and this was especially noticeable after the cell sheet became confluent. The turnover of labelled glucose and derivatives was also enhanced by insulin and this was accompanied by a much higher rate of lactic acid production. It is concluded that insulin does not overcome contact inhibition and permit post-confluent division, but that it does enable the cell to take up and utilize nutrients more efficiently in confluent cultures with a resultant increase in metabolic activity and cell size.

Stabilization of tubulin mRNA by inhibition of protein synthesis in sea urchin embryos

1988 ◽  
Vol 8 (8) ◽  
pp. 3518-3525
Author(s):  
Z Y Gong ◽  
B P Brandhorst
Keyword(s):  
Protein Synthesis ◽  
Sea Urchin ◽  
Mrna Stability ◽  
Rna Synthesis ◽  
Rapid Loss ◽  
Transcription Analysis ◽  
Inhibition Of Protein Synthesis ◽  
Tubulin Mrna ◽  
Autogenous Regulation

An increased level of unpolymerized tubulin caused by depolymerization of microtubules in sea urchin larvae resulted in a rapid loss of tubulin mRNA, which was prevented by nearly complete inhibition of protein synthesis. Results of an RNA run-on assay indicated that inhibition of protein synthesis does not alter tubulin gene transcription. Analysis of the decay of tubulin mRNA in embryos in which RNA synthesis was inhibited by actinomycin D indicated that inhibition of protein synthesis prevents the destabilization of tubulin mRNA. The effect was similar whether mRNA was maintained on polysomes in the presence of emetine or anisomycin or displaced from the polysomes in the presence of puromycin or pactamycin; thus, the stabilization of tubulin mRNA is not dependent on the state of the polysomes after inhibition of protein synthesis. Even after tubulin mRNA declined to a low level after depolymerization of microtubules, it could be rescued by treatment of embryos with inhibitors of protein synthesis. Tubulin mRNA could be induced to accumulate prematurely in gastrulae but not in plutei if protein synthesis was inhibited, an observation that is indicative of the importance of the autogenous regulation of tubulin mRNA stability during embryogenesis. Possible explanations for the role of protein synthesis in the control of mRNA stability are discussed.

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