Co-application of NMDA and dopamine-induced rapid translation of RSK2 in the mature hippocampus.
Ribosomal S6 kinase2 (RSK2) is known to take part in several signal transduction cascades including Mitogen Activated Protein Kinase/Extracellular Regulated Kinase (MAPK/ERK). Following our recent observation that ERK can serve as a coincidence detector for fast and slow neurotransmission in the hippocampus, we analyzed the status of RSK2 phosphorylation subsequent to application of NMDA, dopamine, or both to preparations of mature hippocampal slices in Sprague-Dawley rats. RSK2 was indeed phosphorylated; however, in addition, the amount of RSK2 protein (60%) was induced within 10 min following stimulation. Moreover, the induced expression of RSK2 could be detected in both the cell body layer and the dendrites of hippocampal CA1 cells. Pharmacological analysis showed that RSK2 induction was MAPK ERK Kinase (MEK)-ERK independent, but mammalian Target of Rapamycin (mTOR) and translation dependent. We suggest that the fast kinetics of RSK2 translation that follows physiological stimulations, together with recent observations that its over-expression is vital for the attenuation of major signal transduction cascades, indicate an expanded physiological function of RSK2 in neurons, and sheds new light on the role of RSK2 in the Coffin-Lowry syndrome.
Kaphzan
Hanoch
H
Department of Neurobiology and Ethology, Faculty of Science, Haifa University, Haifa, Israel.
Doron
Guy
G
Rosenblum
Kobi
K
D000818:Animals; D038921:Coffin-Lowry Syndrome / Q000378:metabolism*; D004298:Dopamine / Q000494:pharmacology*; D004790:Enzyme Induction / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D016202:N-Methylaspartate / Q000494:pharmacology*; D009924:Organ Culture Techniques; D010766:Phosphorylation / Q000187:drug effects; D014176:Protein Biosynthesis / Q000187:drug effects; D011494:Protein Kinases / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000096:biosynthesis* / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D058570:TOR Serine-Threonine Kinases
D016202:N-Methylaspartate; D011494:Protein Kinases; D038744:Ribosomal Protein S6 Kinases, 90-kDa; D058570:TOR Serine-Threonine Kinases; C069330:ribosomal protein S6 kinase, 90kDa, polypeptide 3; D020929:Mitogen-Activated Protein Kinase Kinases; D004298:Dopamine