Journal: Molecular Biology of the Cell

Article Title: Localization and retention of p90 ribosomal S6 kinase 1 in the nucleus: implications for its function

doi: 10.1091/mbc.E11-07-0658

Figure Lengend Snippet: RSK1 phosphorylation by PDK1 is required for its nuclear translocation. (A) Schematic of phosphorylation sites on rat RSK1. (B) Top two rows, serum-starved HeLa cells were treated with and without EGF (100 nM) for 10 min and the localization of total RSK1 was monitored with anti-RSK1 antibody; 4′,6-diamidino-2-phenylindole staining shows nuclei. Bottom four rows, the PDK1 inhibitor BX795 inhibits nuclear translocation of RSK1. HeLa cells were treated as described above with and without overnight preincubation with 0.5 μM BX795. The localization of active RSK1 was monitored with anti–phospho-T573-RSK antibody. (C) BX795 inhibits phosphorylation of RSK1 on S221 and S732. Cells were treated as in B. After immunoprecipitation with anti-RSK1 antibody, Western analyses of the immune complexes were performed with anti–phospho RSK antibodies. Scale bar, 10 μm. Representative data from three independent experiments are shown.

Article Snippet: Anti–phospho-RSK1/2 (S221) from R&D Systems (Minneapolis, MN), anti–phospho-RSK (T359/S363) from Cell Signaling (Beverly, MA), anti–phospho-RSK (S380) from Epitomics (Burlingame, CA), anti–phospho-RSK (T573) from Cell Signaling, and anti–phospho-RSK S732 raised by Rockland (Gilbertsville, PA) were used.

Techniques: Phospho-proteomics, Translocation Assay, Staining, Immunoprecipitation, Western Blot