Authors: Shikama, N; Ackermann, R; Brack, C
Abstract: It has been proposed that the decline in protein synthesis observed in aging organisms may result from a decrease in elongation factor EF-1 alpha. Transgenic Drosophila melanogaster flies carrying an additional copy of the EF-1 alpha gene under control of a heat-inducible promoter have an extended lifespan, further indicating that the EF-1 alpha gene may play an important role in determining longevity. To test this hypothesis, we have quantitated EF-1 alpha mRNA, EF-1 alpha protein, and the EF-1 alpha complex-formation activity in these transgenic flies. Furthermore, we have tested whether the transgene construct is functional--i.e., whether transgenic mRNA is induced when flies are grown at higher temperature. The results show that although there is a clear difference in mean lifespan between the EF-1 alpha transgenic (E) flies and the control transgenic (C) flies, E flies do not express more EF-1 alpha protein or mRNA than C flies kept at the same experimental conditions. Although the transgene can be induced when E flies are heat-shocked at 37 degrees C, transgenic mRNA is not detectable in E flies aged at 29 degrees C. In both lines, the loss in catalytic activity with age is the same. We conclude that the E flies examined here do not live longer because of overexpressing the EF-1 alpha gene.
Keywords: Animals; Animals, Genetically Modified; Blotting, Northern; Drosophila melanogaster/*growth & development/metabolism; Gene Expression; Half-Life; Heat-Shock Proteins/genetics; Longevity; Male; Peptide Elongation Factor 1; Peptide Elongation Factors/*biosynthesis/genetics/metabolism; Plasmids; Promoter Regions, Genetic; RNA, Messenger/analysis/biosynthesis; Restriction Mapping; Transcription, Genetic|
Journal: Proc Natl Acad Sci U S A Volume: 91 Issue: 10 Pages: 4199-203 Date: May 10, 1994 PMID: 8183891 |
Shikama, N, Ackermann, R, Brack, C (1994) Protein synthesis elongation factor EF-1 alpha expression and longevity in Drosophila melanogaster. Proc Natl Acad Sci U S A 91: 4199-203.
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