Aminoacyl transfer from phenylalanyl-tRNA microinjected into xenopus laevis oocytes

Xenopus laevis oocytes were injected with [14C] phe-tRNA and the fate of the aminoacyl moiety was studied. The radioactive phenylalanine is gradually hydrolized off the tRNA once inside the cell. The rate of deacylation of the tRNA is not affected by inhibition of cellular protein synthesis by puromycin or cycloheximide. Part of the radioactive amino acid that leaves the tRNA (30 to 65%) is transferred directly into the oocyte nascent proteins as evidenced by the fact that its incorporation into proteins is not reduced by coinjection with a large excess of [12C] phenylalanine. Aminoacyl transfer from injected phe-tRNA into proteins is inhibited by puromycin and cycloheximide. © 1977.