Regulation of protein synthesis factor EF-1 alpha in Mucor racemosus.

The protein synthesis elongation factor EF-1 alpha of Mucor racemosus hyphae contained eight or nine methylated amino acids per molecule, whereas the factor from sporangiospores was nonmethylated. During the course of spore germination, the specific activity of the factor in crude extracts increased sixfold. This increase in activity was accompanied by a constant level of EF-1 alpha-specific mRNA and a constant level of EF-1 alpha protein. Methylation of the protein, however, accelerated during the germination process, in parallel with the increase in specific activity of the factor. We propose that the activity of EF-1 alpha is regulated during germination through methylation of the protein and does not involve transcriptional regulation.