Three genes under different developmental control encode elongation factor 1-alpha in Xenopus laevis.
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.
Djé
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MK
Centre de Génétique Moléculaire, Laboratoire prope du CNRS associé à l'Université P.et M. Curie, Gif-sur-Yvette, France.
Mazabraud
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Viel
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le Maire
M
M
Denis
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Crawford
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Brown
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D005786:Gene Expression Regulation; D005796:Genes; D008099:Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism*; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors / Q000096:biosynthesis / Q000235:genetics*; D012261:Ribonucleoproteins / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D014982:Xenopus laevis
D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors; D012261:Ribonucleoproteins