Premium
Identification of the site on p90 RSK1 that binds the catalytic subunit of PKA
Author(s) -
Gao Xianlong,
Chaturvedi Deepti,
Patel Tarun
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.911.1
Subject(s) - protein subunit , linker , c terminus , chemistry , protein kinase a , kinase , immunoprecipitation , protein kinase domain , microbiology and biotechnology , n terminus , biochemistry , peptide sequence , biology , amino acid , computer science , mutant , gene , operating system
Previously, we reported novel interactions between subunits of cyclic AMP‐dependent protein kinase (PKA) and ribosomal S6 kinase 1 (RSK1). The interactions are dependent upon the activation state of RSK1, with inactive RSK1 associating with the type I regulatory subunit (RI) of PKA whereas active RSK1 binds with the catalytic subunit of PKA (PKAc). Through these interactions, PKA modulates the subcellular localization of RSK1 and thereby its anti‐apoptotic effects. Here we report the identification of the regions of RSK1 that are responsible for the interaction with PKA. We expressed several polypeptides of full‐length RSK1 (aa 1–735) in Hela cells and performed immunoprecipitation with anti‐PKAc antibody. RSK1‐NT (aa 1–317), which contains the N‐terminus kinase domain (NTK) of RSK1, was not co‐precipitated with PKAc, whereas RSK1‐LCT (aa 318–735), which includes the linker region and C‐terminus kinase domain of RSK1, was co‐precipitated with PKAc. Subsequently, we tested RSK1‐NT+Linker (aa 1–418), RSK1‐CT (aa 418–735) and RSK1‐CTK (aa 418–671). RSK1‐CT, but not RSK1‐NT+Linker or RSK1‐CTK, was co‐precipitated with PKAc, indicating that the extreme C‐terminus of RSK1 (aa 671–735) is crucial for the interaction with PKAc. Supported by NIH grant GM 079226