"Consistent with our previous findings in HEK293 cells, incrementSin1 expression in DLD1 cells suppressed Akt Ser473 phosphorylation but had no effect on phosphorylation of the mTORC1 target p70S6K Thr389."
"In agreement with the known food dependent induction, phosphorylation of the mTORC1 target S6K1 on T389 increased after feeding (maximum of phosphorylation was observed at ZT14-ZT22) and then gradually reduced to the minimum level (at ZT6) during the rest period."
"This is an important point because it established that the PA-induced increase in p70 s6k T389 phosphorylation required the presence of mTOR and, therefore, did not result from the presence of a non-specific kinase that was pulled down during the immunoprecipitation procedure."
"Hence, observing a robust increase in p70 s6k T389 phosphorylation, in conjunction with no change in 4E-BP1 T36/45 phosphorylation, was highly unexpected."
"Results revealed that both RPS6KB1 and its phosphorylated protein p-RPS6KB1 at T389 were highly up-regulated in NSCLC tissues, compared with controls; but only the hyperphosphorylation independently predicted the adverse prognosis of NSCLC patients."
"The results demonstrated that PA can induce an increase in p70 s6k T389 phosphorylation, and this only occurred in the immunoprecipitates obtained from the FLAG-mTOR cells."
"Accordingly, stimulated muscle contraction increased mTORC1 signaling in skeletal muscle of control mice; phosphorylation of S6K1 Thr 389 (8-fold), S6K1 Thr 421/Ser424 (7-fold), ribosomal protein S6 (rpS6) Ser 240/244 (8-fold), rpS6 Ser 235/236 10-fold) (data not shown), and 4E-BP1 Ser 65 11-fold) were all significantly increased 2h after muscle contraction (XREF_FIG)."
"The immunoprecipitates were then subjected to an in-vitro mTOR kinase activity assay in which p70 s6k T389 phosphorylation was used as a readout of mTOR activity xref ."
"For example, the RR-mTOR mice enabled us to demonstrate that a mechanically-induced increase in p70 s6k T389 phosphorylation is fully dependent on mTOR."