Targeting of the Akt/PKB kinase to the actin skeleton

V. Cenni, A. Sirri, M. Riccio, G. Lattanzi, S. Santi, A. De Pol, N. M. Maraldi, S. Marmiroli

Research output: Contribution to journalArticle

58 Citations (Scopus)

Abstract

Serine/threonine kinase Akt/PKB intracellular distribution undergoes rapid changes in response to agonists such as Platelet-derived growth factor (PDGF) or Insulin-like growth factor (IGF). The concept has recently emerged that Akt subcellular movements are facilitated by interaction with nonsubstrate ligands. Here we show that Akt is bound to the actin skeleton in in situ cytoskeletal matrix preparations from PDGF-treated Saos2 cells, suggesting an interaction between the two proteins. Indeed, by immunoprecipitation and subcellular fractioning, we demonstrate that endogenous Akt and actin physically interact. Using recombinant proteins in in vitro binding and overlay assays, we further demonstrate that Akt interacts with actin directly. Expression of Akt mutants strongly indicates that the N-terminal PH domain of Akt mediates this interaction. More important, we show that the partition between actin bound and unbound Akt is not constant, but is modulated by growth factor stimulation. In fact, PDGF treatment of serum-starved cells triggers an increase in the amount of Akt associated with the actin skeleton, concomitant with an increase in Akt phosphorylation. Conversely, expression of an Akt mutant in which both Ser473 and Thr308 have been mutated to alanine completely abrogates PDGF-induced binding. The small GTPases Rac1 and Cdc42 seem to facilitate actin binding, possibly increasing Akt phosphorylation.

Original languageEnglish
Pages (from-to)2710-2720
Number of pages11
JournalCellular and Molecular Life Sciences
Volume60
Issue number12
DOIs
Publication statusPublished - Dec 2003

Fingerprint

Skeleton
Actins
Phosphotransferases
Platelet-Derived Growth Factor
Phosphorylation
Monomeric GTP-Binding Proteins
Protein-Serine-Threonine Kinases
Somatomedins
Immunoprecipitation
Recombinant Proteins
Cell Communication
Alanine
actin kinase
Assays
Intercellular Signaling Peptides and Proteins
Cells
Ligands
Serum
Proteins

Keywords

  • Akt
  • Cdc42
  • Cytoskeleton
  • GFP-actin
  • PDGF
  • Rac

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Cell Biology

Cite this

Cenni, V., Sirri, A., Riccio, M., Lattanzi, G., Santi, S., De Pol, A., ... Marmiroli, S. (2003). Targeting of the Akt/PKB kinase to the actin skeleton. Cellular and Molecular Life Sciences, 60(12), 2710-2720. https://doi.org/10.1007/s00018-003-3349-4

Targeting of the Akt/PKB kinase to the actin skeleton. / Cenni, V.; Sirri, A.; Riccio, M.; Lattanzi, G.; Santi, S.; De Pol, A.; Maraldi, N. M.; Marmiroli, S.

In: Cellular and Molecular Life Sciences, Vol. 60, No. 12, 12.2003, p. 2710-2720.

Research output: Contribution to journalArticle

Cenni, V, Sirri, A, Riccio, M, Lattanzi, G, Santi, S, De Pol, A, Maraldi, NM & Marmiroli, S 2003, 'Targeting of the Akt/PKB kinase to the actin skeleton', Cellular and Molecular Life Sciences, vol. 60, no. 12, pp. 2710-2720. https://doi.org/10.1007/s00018-003-3349-4
Cenni, V. ; Sirri, A. ; Riccio, M. ; Lattanzi, G. ; Santi, S. ; De Pol, A. ; Maraldi, N. M. ; Marmiroli, S. / Targeting of the Akt/PKB kinase to the actin skeleton. In: Cellular and Molecular Life Sciences. 2003 ; Vol. 60, No. 12. pp. 2710-2720.
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