Raf kinases mediate the phosphorylation of eukaryotic translation elongation factor 1A and regulate its stability in eukaryotic cells
Zitieren Sie bitte immer diese URN: urn:nbn:de:bvb:20-opus-134673
- We identified eukaryotic translation elongation factor 1A (eEF1A) Raf-mediated phosphorylation sites and defined their role in the regulation of eEF1A half-life and of apoptosis of human cancer cells. Mass spectrometry identified in vitro S21 and T88 as phosphorylation sites mediated by B-Raf but not C-Raf on eEF1A1 whereas S21 was phosphorylated on eEF1A2 by both B-and C-Raf. Interestingly, S21 belongs to the first eEF1A GTP/GDP-binding consensus sequence. Phosphorylation of S21 was strongly enhanced when both eEF1A isoforms were preincubatedWe identified eukaryotic translation elongation factor 1A (eEF1A) Raf-mediated phosphorylation sites and defined their role in the regulation of eEF1A half-life and of apoptosis of human cancer cells. Mass spectrometry identified in vitro S21 and T88 as phosphorylation sites mediated by B-Raf but not C-Raf on eEF1A1 whereas S21 was phosphorylated on eEF1A2 by both B-and C-Raf. Interestingly, S21 belongs to the first eEF1A GTP/GDP-binding consensus sequence. Phosphorylation of S21 was strongly enhanced when both eEF1A isoforms were preincubated prior the assay with C-Raf, suggesting that the eEF1A isoforms can heterodimerize thus increasing the accessibility of S21 to the phosphate. Overexpression of eEF1A1 in COS 7 cells confirmed the phosphorylation of T88 also in vivo. Compared with wt, in COS 7 cells overexpressed phosphodeficient (A) and phospho-mimicking (D) mutants of eEF1A1 (S21A/D and T88A/D) and of eEF1A2 (S21A/D), resulted less stable and more rapidly proteasome degraded. Transfection of S21 A/D eEF1A mutants in H1355 cells increased apoptosis in comparison with the wt isoforms. It indicates that the blockage of S21 interferes with or even supports C-Raf induced apoptosis rather than cell survival. Raf-mediated regulation of this site could be a crucial mechanism involved in the functional switching of eEF1A between its role in protein biosynthesis and its participation in other cellular processes.…
Autor(en): | C. Sanges, C. Scheuermann, R. P. Zahedi, A. Sickmann, A. Lamberti, N. Migliaccio, A. Baljuls, M. Marra, S. Zappavigna, U. Rapp, A. Abbruzzese, M. Caraglia, P. Arcari |
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URN: | urn:nbn:de:bvb:20-opus-134673 |
Dokumentart: | Artikel / Aufsatz in einer Zeitschrift |
Institute der Universität: | Medizinische Fakultät / Institut für Medizinische Strahlenkunde und Zellforschung |
Fakultät für Biologie / Theodor-Boveri-Institut für Biowissenschaften | |
Sprache der Veröffentlichung: | Englisch |
Titel des übergeordneten Werkes / der Zeitschrift (Englisch): | Cell Death & Disease |
Erscheinungsjahr: | 2012 |
Band / Jahrgang: | 3 |
Heft / Ausgabe: | e276 |
Originalveröffentlichung / Quelle: | Cell Death and Disease (2012) 3, e276; doi:10.1038/cddis.2012.16 |
DOI: | https://doi.org/10.1038/cddis.2012.16 |
Allgemeine fachliche Zuordnung (DDC-Klassifikation): | 6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit |
Freie Schlagwort(e): | EF-1A; Raf kinases; aminoacyl-transfer-RNA; apoptosis; cancer-cells; chain; elongation; factor 1-alpha; factor EEF1A2; lung cancer; mass spectrometry; nucleotide exchange; polyarcylamide gels; protein docking; signal transduction; tyrosine phosphorylation; ubiquitin |
Datum der Freischaltung: | 09.11.2017 |
Lizenz (Deutsch): | CC BY-NC-ND: Creative-Commons-Lizenz: Namensnennung, Nicht kommerziell, Keine Bearbeitung |