title: Identification of elongation factor 1alpha as a potential associated binding partner for Akt2.
abstract: Akt protein kinase has been shown to play a pivotal role in diverse cell functions, including motility, apoptosis, growth and metabolism. How it differentially regulates these diverse functions is of significant interest. Three isoforms have been well characterized, Akt1, 2, and 3, encoded by separate genes, but showing high homology over the entire coding sequence (> 80%). An area of variability between the three isoforms is the C-terminal tail. To find potentially regulating binding partners of Akt2, the isoform implicated in metabolic control, we used a glutathione-S-transferase (GST) fusion protein expressing the C-terminal 75 residues of Akt2 (GST-Akt2 tail) to screen for proteins that specifically bound the Akt2 tail. Elongation factor 1alpha (EF1alpha) and beta-tubulin were identified as binding partners for the Akt2 tail by peptide mass fingerprinting. These two proteins have themselves been previously identified as interacting partners (Nakazawa et al.FEBS Lett. 453,29-34, 1999). Using CHOT cells that overexpress insulin receptors and HA-tagged Akt2, we showed that EF1alpha co-immunoprecipitated with HA-tagged Akt2. It is thus possible that these proteins colocalise as part of a regulatory signaling complex with the cytoskeleton directing them to sites of cell activity.
authors.affiliation: CSIRO Olecular and health Technologies, 343 Royal Parade, Parkville, 3052 Victoria, Australia.
authors.forename: Janet
authors.initials: J
authors.lastname: Lau
authors.forename: Laura A
authors.initials: LA
authors.lastname: Castelli
authors.forename: Emme C K
authors.initials: EC
authors.lastname: Lin
authors.forename: S Lance
authors.initials: SL
authors.lastname: Macaulay
mesh_terms: D041721:3T3-L1 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D016466:CHO Cells; D002457:Cell Extracts; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004591:Electrophoresis, Polyacrylamide Gel; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D006801:Humans; D047468:Immunoprecipitation; D051379:Mice; D008969:Molecular Sequence Data; D020648:Peptide Elongation Factor 1 / Q000378:metabolism*; D011485:Protein Binding; D051057:Proto-Oncogene Proteins c-akt / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D002457:Cell Extracts; D020648:Peptide Elongation Factor 1; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase; C494921:AKT2 protein, human; D051057:Proto-Oncogene Proteins c-akt