Description
The p90 ribosomal S6 kinases (RSK) 1-
4 are downstream members of the extracellular signal-
regulated kinase (ERK)/MAPK cascade. SL 0101-
1 is a kaempferol glycoside, isolated from the tropical plant
F. refracta, that selectively inhibits RSK2 with an IC
50 value of 89 nM (K
i = 1 μM) without interfering with upstream activators of RSK, including ERK, MEK, EGFR, and PKC. At 100 μM, SL 0101-
1 inhibits the proliferation of MCF-
7 breast cancer cells, arresting cells in the G
1 phase of the cell cycle. SL 0101-
1 has been used to characterize the intracellular signaling events associated with angiotensin II-
induced tyrosine kinase activation with a concentration of 30 μM attenuating angiotensin II-
induced cell proliferation.
Uses
SL 0101 is a potent and selective inhibitor of p90 Rsk, without inhibiting the function of upstream kinases such as MEK, Raf, or PKC.
Biological Activity
Selective inhibitor of p90 ribosomal S6 kinase (RSK) (IC 50 = 89 nM for RSK2). Does not inhibit upstream kinases such as MEK, Raf and PKC.? Inhibits the growth of MCF-7 human breast cancer cells with no effect on the normal breast cell line.
