Aminoacyl-sRNA synthetases as possible regulators of protein synthesis in the embryo of the sea urchin Paracentrotus lividus.

The low protein synthetic activity of the unfertilized sea urchin egg is attributed to a translational inhibition.1 Most of the attention has focused on the ribosomes, which have proved to be unable to engage in protein synthesis before fertilization.2' 3 The other components for the translation of messenger ribonucleic acid (mRNA) have not been thoroughly studied; in particular, very little is known as to whether or not transfer ribonucleic acids (tRNA) and aminoacyl-sRNA synthetases (EC 6.1.1) play any role in this process. Suggestions to this effect come from the work of Glisin and Glisin4 and Nemer and Bard.5