Temperature sensitivity of phospho-Ser(473)-PKB/AKT.
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Temperature sensitivity of phospho-Ser(473)-PKB/AKT. / Oehler-Jänne, Christoph; von Bueren, André; André, O; Vuong, Van; Hollenstein, Andreas; Grotzer, Michael A; Pruschy, Martin.
in: BIOCHEM BIOPH RES CO, Jahrgang 375, Nr. 3, 3, 2008, S. 399-404.Publikationen: SCORING: Beitrag in Fachzeitschrift/Zeitung › SCORING: Zeitschriftenaufsatz › Forschung › Begutachtung
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T1 - Temperature sensitivity of phospho-Ser(473)-PKB/AKT.
AU - Oehler-Jänne, Christoph
AU - von Bueren, André
AU - André, O
AU - Vuong, Van
AU - Hollenstein, Andreas
AU - Grotzer, Michael A
AU - Pruschy, Martin
PY - 2008
Y1 - 2008
N2 - The phospho-PKB/Akt status is often used as surrogate marker to measure activation of the PI3K/Akt/mTOR signal transduction pathway. Though, inconsistencies of the p-Ser(473)-PKB/Akt status have raised doubts in the validity of p-Ser(473)-PKB/Akt phosphorylation as endpoint. Here, we determined that p-Ser(473)-PKB/Akt but not p-Thr(308)-PKB/Akt phosphorylation is highly temperature sensitive. p-Ser(473)-PKB/Akt phosphorylation was rapidly reduced to levels below 50% on exposure to 20-25 degrees C in murine and human cell lines including cells expressing constitutively active PI3K or lacking PTEN. Down-regulation of p-Ser(473)-PKB/Akt was reversible and re-exposure to physiological temperature resulted in increased p-Ser(473)-PKB/Akt phosphorylation levels. Phosphatase activity at low temperature was sustained at 75% baseline level and phosphatase inhibition prevented p-Ser(473)-PKB/Akt dephosphorylation induced by the low temperature shift. Interestingly temperature-dependent deregulation of the p-Ser(473)-PKB/Akt status was also observed in response to irradiation. Thus our data demonstrate that minimal additional stress factors deregulate the PI3K/Akt-survival pathway and the p-Ser(473)-PKB/Akt status as experimental endpoint.
AB - The phospho-PKB/Akt status is often used as surrogate marker to measure activation of the PI3K/Akt/mTOR signal transduction pathway. Though, inconsistencies of the p-Ser(473)-PKB/Akt status have raised doubts in the validity of p-Ser(473)-PKB/Akt phosphorylation as endpoint. Here, we determined that p-Ser(473)-PKB/Akt but not p-Thr(308)-PKB/Akt phosphorylation is highly temperature sensitive. p-Ser(473)-PKB/Akt phosphorylation was rapidly reduced to levels below 50% on exposure to 20-25 degrees C in murine and human cell lines including cells expressing constitutively active PI3K or lacking PTEN. Down-regulation of p-Ser(473)-PKB/Akt was reversible and re-exposure to physiological temperature resulted in increased p-Ser(473)-PKB/Akt phosphorylation levels. Phosphatase activity at low temperature was sustained at 75% baseline level and phosphatase inhibition prevented p-Ser(473)-PKB/Akt dephosphorylation induced by the low temperature shift. Interestingly temperature-dependent deregulation of the p-Ser(473)-PKB/Akt status was also observed in response to irradiation. Thus our data demonstrate that minimal additional stress factors deregulate the PI3K/Akt-survival pathway and the p-Ser(473)-PKB/Akt status as experimental endpoint.
M3 - SCORING: Zeitschriftenaufsatz
VL - 375
SP - 399
EP - 404
JO - BIOCHEM BIOPH RES CO
JF - BIOCHEM BIOPH RES CO
SN - 0006-291X
IS - 3
M1 - 3
ER -