PHOSPHORYLATION OF ELONGATION FACTOR-II FROM THE LEPIDOPTERAN INSECT,SPODOPTERA-FRUGIPERDA

In mammalian cells, protein synthesis can be regulated at the level of elongation by the phosphorylation of elongation factor 2 (eEF-2) by a highly specific Ca2+/calmodulin-dependent kinase. In this report, we show that eEF-2 from a cell line derived from the insect, Spodoptera f rugiperda, is a substrate for mammalian eEF-2 kinase and that phosphor ylation is Ca2+-dependent. Furthermore, two-dimensional peptide mappin g shows that the kinase phosphorylates the same sites in Spodoptera eE F-2 as those phosphorylated in the rabbit protein. However, we were un able to detect an eEF-2 kinase in Spodoptera cells.