Identification of S6K2 as a centrosome-located kinase.
Ribosomal S6 kinase 2 (S6K2) acts downstream of the mammalian target of rapamycin (mTOR). Here, we show that some S6K2 localize at the centrosome throughout the cell cycle. S6K2 is found in the pericentriolar area of the centrosome. S6K2 centrosomal localization is unaffected by serum withdrawal or treatment with rapamycin, wortmannin, U0126, or phorbol-12-myristate-13-acetate (PMA). Unlike S6K2, S6 kinase 1 (S6K1) does not localize at the centrosome, suggesting the two kinases may also have nonoverlapping functions. Our data suggest that centrosomal S6K2 may have a role in the phosphoinositide-3-kinase (PI3K)/Akt/mTOR signaling pathway that has also been detected in the centrosome.
Rossi
Rossella
R
Istituto di Genetica Molecolare (IGM) - CNR, 27100 Pavia, Italy.
Pester
John M
JM
McDowell
Mitch
M
Soza
Samuela
S
Montecucco
Alessandra
A
Lee-Fruman
Kay K
KK
D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology*; D018385:Centrosome / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D019893:Ribosomal Protein S6 Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D058570:TOR Serine-Threonine Kinases
D004791:Enzyme Inhibitors; D019869:Phosphatidylinositol 3-Kinases; D011494:Protein Kinases; D051057:Proto-Oncogene Proteins c-akt; D019893:Ribosomal Protein S6 Kinases; D058570:TOR Serine-Threonine Kinases; C546842:MTOR protein, human