Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
Date (from‐to) : 1999/04 -2001/03
Author : EJIRI Shin-ichiro; KIDOU Shin-ichiro
Elongation factor EF-1 consists of four subunits (EF-1 αββ'γ). EF-1α・GTP catalyzes the binding of aminoacyl-tRNA to the ribosome. EF-1β and EF-1β' catalyze the GOP/GTP exchange on EF-1α・GDP, However, the function of EF-1γ, a subunit detected in eukaryotes, but not in prokaryotes remained unknown. In this studies we demonstrated that rice EF-1ββ'γ and recombinant EF-1γ possess glutathione Stransferase (GST) activity. The EF-1ββ'γ-or EF-1γ- dependent GST activity is about one-fiftieth of the rice GST activity. This is the first indication of glutathione Stransferase activity in EF-1γ. Moreover, we demonstrated that EF-1α-GFP and EF1γ-GFP are co-localized with actin filaments in the cytoplasm of tobacco BY-2 cell at interphase. Surprisingly, both fusion proteins are located on spindle bodies at the stage of nuclear fission. As moonlighting functions of EF-1, such as cytoskeietal organization, apoptosis, and oncogenic transformation. have been reported, our results will facilitate the understanding of the underlying molecular mechanisms of these processes.