MATERNAL mRNA AND PROTEIN SYNTHESIS IN THE EMBRYO

1973 ◽  
Vol 74 (Suppl) ◽  
pp. S244-S262 ◽  
Author(s):  
P. R. Gross ◽  
K. W. Gross ◽  
A. I. Skoultchi ◽  
J. V. Ruderman
Keyword(s):  
Protein Synthesis ◽  
Sea Urchin ◽  
Messenger Rna ◽  
Direct Proof ◽  
Indirect Evidence ◽  
Translation Control ◽  
Histone Mrna ◽  
Translational Machinery ◽  
Maternal Mrna ◽  
Histone Synthesis

ABSTRACT According to the masked maternal messenger RNA hypothesis, a large part if not all the protein synthesis of early development is directed by mRNA already present in the cytoplasm of unfertilized eggs. This mRNA is supposed to be synthesized during oogenesis and stored in some unavailable form until some later time in development, when it is selectively associated with the translational machinery. To the indirect evidence, which is nevertheless very strong, there can now be added a direct proof of the hypothesis for the case of histone mRNA. The five main histones of sea urchin embryos are synthesized on small polyribosomes, directed in part by newly-synthesized messages that sediment as a group at about 9S. Some histone synthesis survives total transcription block, however, suggesting that maternal histone mRNA exists. In competition-hybridization experiments, the egg RNA is shown to contain sequences characteristic of functional, embryonic histone mRNA. The competing RNA is localized in ribonucleoprotein particles of egg homogenates that sediment at 20–40S. These same particles contain RNA that stimulates a cell-free heterologous system to synthesize sea urchin histones. The application of these facts to some problems of translation control and of development generally is discussed.

scholarly journals THE EFFECT OF PROTEIN SYNTHESIS INHIBITION ON THE ENTRY OF MESSENGER RNA INTO THE CYTOPLASM OF SEA URCHIN EMBRYOS

1971 ◽  
Vol 49 (3) ◽  
pp. 692-701 ◽  
Author(s):  
Brigid Hogan ◽  
Paul R. Gross
Keyword(s):  
Protein Synthesis ◽  
Sea Urchin ◽  
Messenger Rna ◽  
Potent Inhibitor ◽  
Protein Synthesis Inhibition ◽  
Embryonic Cells ◽  
Synthesis Inhibition ◽  
Uridine Incorporation ◽  
Sea Urchin Embryos ◽  
Inhibitor Of Protein Synthesis

Emetine is a potent inhibitor of protein synthesis in sea urchin embryos. At a concentration of the drug that rapidly inhibits protein synthesis in blastulae by 95%, uridine incorporation into RNA continues for more than 1 hr and presumptive histone messenger RNA is synthesized and transported into the cytoplasm where it is apparently associated with polyribosomes. Possible explanations of this result and its implications for the "informasome" theory of messenger transport in embryonic cells are discussed.

scholarly journals Ionizing Radiation and Translation Control: A Link to Radiation Hormesis?

2020 ◽  
Vol 21 (18) ◽  
pp. 6650
Author(s):  
Usha Kabilan ◽  
Tyson E. Graber ◽  
Tommy Alain ◽  
Dmitry Klokov
Keyword(s):  
Protein Synthesis ◽  
Ionizing Radiation ◽  
Molecular Mechanisms ◽  
Low Dose ◽  
Mrna Translation ◽  
Cellular Responses ◽  
Translation Control ◽  
Cis Acting ◽  
Radiation Hormesis ◽  
Downstream Signaling

Protein synthesis, or mRNA translation, is one of the most energy-consuming functions in cells. Translation of mRNA into proteins is thus highly regulated by and integrated with upstream and downstream signaling pathways, dependent on various transacting proteins and cis-acting elements within the substrate mRNAs. Under conditions of stress, such as exposure to ionizing radiation, regulatory mechanisms reprogram protein synthesis to translate mRNAs encoding proteins that ensure proper cellular responses. Interestingly, beneficial responses to low-dose radiation exposure, known as radiation hormesis, have been described in several models, but the molecular mechanisms behind this phenomenon are largely unknown. In this review, we explore how differences in cellular responses to high- vs. low-dose ionizing radiation are realized through the modulation of molecular pathways with a particular emphasis on the regulation of mRNA translation control.

scholarly journals Protein synthesis in the dendrite

2002 ◽  
Vol 357 (1420) ◽  
pp. 521-529 ◽  
Author(s):  
Shao Jun Tang ◽  
Erin M. Schuman
Keyword(s):  
Protein Synthesis ◽  
Neural Plasticity ◽  
Messenger Rna ◽  
Mrna Translation ◽  
Synaptic Activity ◽  
Synaptic Proteins ◽  
Local Source ◽  
Synaptic Protein ◽  
Specific Proteins ◽  
Molecular Nature

In neurons, many proteins that are involved in the transduction of synaptic activity and the expression of neural plasticity are specifically localized at synapses. How these proteins are targeted is not clearly understood. One mechanism is synaptic protein synthesis. According to this idea, messenger RNA (mRNA) translation from the polyribosomes that are observed at the synaptic regions provides a local source of synaptic proteins. Although an increasing number of mRNA species has been detected in the dendrite, information about the synaptic synthesis of specific proteins in a physiological context is still limited. The physiological function of synaptic synthesis of specific proteins in synaptogenesis and neural plasticity expression remains to be shown. Experiments aimed at understanding the mechanisms and functions f synaptic protein synthesis might provide important information about the molecular nature of neural plasticity.

scholarly journals SYNTHESIS AND STORAGE OF MICROTUBULE PROTEINS BY SEA URCHIN EMBRYOS

1971 ◽  
Vol 50 (2) ◽  
pp. 516-528 ◽  
Author(s):  
Rudolf A. Raff ◽  
Gerald Greenhouse ◽  
Kenneth W. Gross ◽  
Paul R. Gross
Keyword(s):  
Amino Acids ◽  
Sea Urchin ◽  
Messenger Rna ◽  
Binding Activity ◽  
Total Soluble Protein ◽  
Cell Stage ◽  
Lytechinus Pictus ◽  
Sea Urchin Embryos ◽  
Tritiated Amino Acids ◽  
Vinblastine Sulfate

Studies employing colchicine binding, precipitation with vinblastine sulfate, and acrylamide gel electrophoresis confirm earlier proposals that Arbacia punctulata and Lytechinus pictus eggs and embryos contain a store of microtubule proteins. Treatment of 150,000 g supernatants from sea urchin homogenates with vinblastine sulfate precipitates about 5% of the total soluble protein, and 75% of the colchicine-binding activity. Electrophoretic examination of the precipitate reveals two very prominent bands. These have migration rates identical to those of the A and B microtubule proteins of cilia. These proteins can be made radioactive at the 16 cell stage and at hatching by pulse labeling with tritiated amino acids. By labeling for 1 hr with leucine-3H in early cleavage, then culturing embryos in the presence of unlabeled leucine, removal of newly synthesized microtubule proteins from the soluble pool can be demonstrated. Incorporation of labeled amino acids into microtubule proteins is not affected by culturing embryos continuously in 20 µg/ml of actinomycin D. Microtubule proteins appear, therefore, to be synthesized on "maternal" messenger RNA. This provides the first protein encoded by stored or "masked" mRNA in sea urchin embryos to be identified.

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