Three genes under different developmental control encode elongation factor 1-α inXenopus laevis

Abstract

We have cloned cDNAs encoding two variants of the elongation factor for protein synthesis in Xenopus laevis, called EF-1 alpha. One of these (42Sp50) is expressed exclusively in immature oocytes. It is one of two protein components of a 42S RNP particle that is very abundant in previtellogenic oocytes. The 42S RNP particle consists of various tRNAs, 5S RNA, 42Sp50 and a 5S RNA binding protein (42Sp43). A major function served by 42Sp50 appears to be the storage of tRNAs for later use in oogenesis and early embryogenesis. The second EF-1 alpha variant (EF-1 alpha O) is expressed mainly in oocytes but transiently in early embryogenesis as well. Its mRNA cannot be detected after neurulation in somatic cells. EF-1 alpha O is closely related to a third EF-1 alpha (EF-1 alpha S), discovered originally by Krieg et al. (1). EF-1 alpha S is expressed at low levels in oocytes but actively in somatic cells. The latter two proteins are very similar to known eukaryotic EF-1 alpha from other organisms and presumably function in their respective cell types to support protein synthesis.

Identification of a developmentally regulated translation elongation factor 2 in Tetrahymena thermophila

“…Nevertheless, there are examples in multicellular eukaryotes of differential expression of isoforms of translation elongation factor 1A (eEF1A). In Drosophila and Xenopus, there is evidence that one EF1A gene is continuously expressed and one or two others are developmentally regulated (Hovemann et al, 1988, Djé et al, 1990. In mammals, the eEF1A2 gene is expressed in heart and muscle tissue and eventually becomes the only isoform expressed in these tissues (Knudsen et al, 1993).…”

The application of expression analysis in elucidating the eukaryotic elongation factor one alpha gene family in Arabidopsis thaliana

“…The nuclear location may be associated with an interaction between eEF1A and the transcription factor ZPR1 (Gangwani et al 1998). A1, A3, and A4 have also been located at the plasma membrane, and may function in activation of PI4-Kinase (Yang et al 1993) or interaction with microtubules (Djé et al 1990) closely associated in the region. The A1 and A2 proteins were also localized to the vacuole.…”

“…These genes were expressed in the ear, leaf, root, silk and stem tissues, but at diVerent levels. However, no evidence of tissue-speciWc or developmental-stage speciWc gene expression has been reported for eEF1A in plants (Kidou and Ejiri 1998;Carneiro et al 1999), results incongruent to those exhibited in animals (Djé et al 1990;Knudsen et al 1993;Kahns et al 1998).…”

Translation elongation factor 1A2 is encoded by one of four closely related eef1a genes and is dispensable for survival in zebrafish

“…Two sequence-redundant eEF1A genes TEF1 and TEF2 are present in the yeast Saccharomyces cerevisiae [4,5]. In Drosophila melanogaster, two genes, F1 and F2, have been described (Hovemann et al [6]) while four and five eEF1A genes have been reported in Xenopus laevis and Solea senegalensis, respectively [7][8][9].…”