IndraLab

"Similarly, p70 S6 kinase mediated phosphorylation of ribosomal S6 at S235 and S240 was comparable between WT and Dapk -/- T cells (XREF_SUPPLEMENTARY)."

"Similarly, p70 S6 kinase-mediated phosphorylation of ribosomal S6 at S235 and S240 was comparable between WT and Dapk −/− T cells ( xref )."

"A recent bioinformatics study performed KEGG analysis and gene set enrichment analysis (GSEA) via Gene Expression Profiling Interactive Analysis (GEPIA) based on The Cancer Genome Atlas (TCGA) datasets and demonstrated that ACTL6A significantly affects ribosomal pathways. xref Since S6 kinase (S6K1) is a key member of the pathway, that participates in translational control, and the S6 kinase (S6K1)-S6 signaling pathway is critical for regulating proliferation and survival in response to growth factors, we focused on S6K1 as a downstream target of ACTL6A. xref S6K1 always phosphorylates S6 protein at Ser235, Ser236, Ser240, Ser244, and Ser247. xref Aberrant upregulation of S6 phosphorylation and increased S6K activity are frequently present in various tumors including ESCC. xref Although phosphorylated-ribosomal protein S6 (p-S6) is considered to be a potential target in ESCC in vitro and S6 phosphorylation has prognostic significance in ESCC, the relationship between S6 and ACTL6A remains unclear. xref "

"The ribosomal protein S6 is a component of the 40S ribosomal subunit and is phosphorylated at Ser 240/244 by p70S6 kinase (S6K1), a direct target of mTORC1."

"Furthermore, inhibition of p70S6K with LY2584702 reduced RPS6 phosphorylation at S235:236 and S240:244 in the E420K and E198K variant cell lines (Figure 6D–F)."

"S6 is phosphorylated by both S6K1 and the closely related S6K2 on Ser 240 / Ser 244 as well as Ser 235 / Ser 236."

No evidence text available

"The great reduction of p-S6(S235) levels by gefitinib and of p-S6(S240) by rapamycin (Fig. 1B) support the conclusion that these sites are phosphorylated by RSK and S6K1, respectively. On the other hand, rapamycin inhibition of mTORC1 and consequently inactive S6K1 also markedly reduced p-S6(S235) levels, despite RSK remaining active as evidenced by the maintenance of p-eIF4B levels in the presence of rapamycin (Fig. 1B). These results are consistent with the conclusion that phosphorylation of S6(S240) by S6K1 is an essential prerequisite for subsequent phosphorylation of S6(S235) by RSK."

"Its phosphorylation serves as a robust readout of mTORC1 activity, since rpS6 is phosphorylated at Serine 240 and 244 specifically by p70S6K, which is itself activated by direct phosphorylation of Thr389 by mTORC1 [24–26]."

"These results are consistent with the conclusion that phosphorylation of S6 (S240) by S6K1 is an essential prerequisite for subsequent phosphorylation of S6 (S235) by RSK."

"The p70 ribosomal S6 kinases, directly regulated by mTOR, phosphorylate rpS6 on Ser 240 and Ser 244."

"After stimulation, S6K1 phosphorylates S6 on five serine residues (S235, S236, S240, S244, and S247) within the C-terminus [XREF_BIBR]."

"The experiments described here have identified phosphorylation of ribosomal protein S6 at its S240 and S235 residues as specific readouts of mTOR hyperactivity vs. combined mTOR and MAPK hyperactivity, respectively. Early test tube studies using purified rat S6K1 and ribosomes concluded that S6K1 can phosphorylate both sites on S6 [47]. Subsequent studies in cells [48], [49] found that RSK is primarily responsible for S6(S235) phosphorylation and perusal of the data in these reports suggested to us that S235 phosphorylation is dependent upon or greatly enhanced by prior S240 phosphorylation by S6K1."

"The experiments described here have identified phosphorylation of ribosomal protein S6 at its S240 and S235 residues as specific readouts of mTOR hyperactivity vs. combined mTOR and MAPK hyperactivity, respectively. Early test tube studies using purified rat S6K1 and ribosomes concluded that S6K1 can phosphorylate both sites on S6 [47]. Subsequent studies in cells [48], [49] found that RSK is primarily responsible for S6(S235) phosphorylation and perusal of the data in these reports suggested to us that S235 phosphorylation is dependent upon or greatly enhanced by prior S240 phosphorylation by S6K1. Our results establish clearly that in premalignant keratinocytes and SCC cells S6(S235) phosphorylation is accomplished exclusively by RSK and requires prior phosphorylation of S240 by S6K1."

"Subsequent studies in cells [48], [49] found that RSK is primarily responsible for S6(S235) phosphorylation and perusal of the data in these reports suggested to us that S235 phosphorylation is dependent upon or greatly enhanced by prior S240 phosphorylation by S6K1."