Figure 4.

Levels of phospho-Ser129 α-syn are decreased by the mTOR inhibitor rapamycin. SH-SY5Y cells were pretreated with retinoic acid and tetracycline. Cells were then incubated for 16 h with no addition or in the presence of 2 μM rapamycin. Levels of RPS6, p-RPS6, hα-syn, phospho-Ser129 hα-syn and tubulin were assayed by immunoblotting (a). Semiquantitative analysis of band intensities is expressed as hα-syn/tubulin ratio (b) or phospho-Ser129 hα-syn/hα-syn ratio (c). In separate experiments, cells were incubated for 16 h with no addition or in the presence of OKA alone (15 nM), rapamycin alone (2 μM) or both OKA and rapamycin. Levels of hα-syn, phospho-Ser129 hα-syn and tubulin were assayed by immunoblotting (d). Semiquantitative analysis of band intensities is expressed as phospho-Ser129 hα-syn/hα-syn ratio (e). Data in (b, c and e) are the means±S.E.M. of at least three independent experiments. **P<0.01 and ***P<0.001 versus the respective control group (black bar). ^†††P<0.001 versus the group treated with OKA alone. ^###P<0.001 versus the group treated with both OKA and rapamycin