Kainic acid causes mTOR activation and translocation from cytosol to the nucleus – Live imaging study

• Autorzy: Macias M. , Janusz-Kaminska A. , Tarkowski B. , Gozdz A. , Jaworski J.
• Języki publikacji: EN

Abstrakty

EN

INTRODUCTION: The mechanistic target of rapamycin (mTOR) is a protein kinase, which integrates eukaryotic cell growth, metabolism and external stimuli. Most research link mTOR with control of protein translation but recent studies revealed additional mTOR function in cell nucleus. Previously, we showed that phosphorylation of mTOR (Ser2448; P-mTOR) is upregulated in neuronal nucleus upon kainate (KA) induced status epilepticus. Whether other stimuli have the same effect on nuclear mTOR phosphorylation and if increased nuclear import of mTOR contributes to this phenomenon remained unknown. Also it was not known if nuclear transport of other proteins affects mTOR signaling. AIM(S): To analyze effects of neuronal activity on nuclear translocation of mTOR and its nuclear activity. To analyze importance of nuclear transport for mTOR signaling. METHOD(S): Cultured hippocampal neurons were treated with: KA, BDNF; NMDA and chemical LTP (cLTP) protocol or TTX. mTOR activity was measured with FRET method. mTOR nuclear translocation was assessed using FRAP. Nuclear import was blocked with importazole. Immunofluorescence of P-S6 protein was used as a marker of mTOR activity. RESULTS: We found that KA, BDNF, NMDA and cLTP caused nuclear upregulation of P-mTOR. However, TTX or cLTD had no effect. FRAP and FRET revealed that mTOR activity due to KA treatment is first observed in cytosol and then in nucleus, where mTOR is translocated upon treatment. Blocking nuclear import silenced mTOR activity in response to KA and inhibited P-mTOR upregulation in the nucleus. CONCLUSIONS: Our experiments showed that increased neuronal activity upregulates nuclear P-mTOR and increases nuclear activity of mTOR due to nuclear translocation of the kinase. FINANCIAL SUPPORT: The research was supported by PNSC grants no. 2012/05/B/NZ3/00429 and 2012/07/E/ NZ3/00503.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2017
• Tom: 77
• Numer: Suppl.1
• Opis fizyczny: p.114-115

Twórcy

autor

Macias M.

• Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Warsaw, Poland

autor

Janusz-Kaminska A.

• Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Warsaw, Poland

autor

Tarkowski B.

• Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Warsaw, Poland

autor

Gozdz A.

• Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Warsaw, Poland

autor

Jaworski J.

• Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Warsaw, Poland