The p70S6K activation is not regulated by PTEN status and transmits signal downstream of PI 3′K in mouse PCT lines.

(A) Various cell lines were serum starved and either untreated or stimulated with IGF-I for 10 minutes. When wortmannin (100 nmol/L; abbreviated as w or wort in the figure) was included, it was added 20 minutes before IGF-I stimulation. Equivalent amounts of cell lysates were immunoprecipitated with anti-p70S6K or anti-Grb2 (negative control). Washed immunoprecipitates were subjected to an in vitro p70S6K activity assay according to the protocol from the manufacturer. Results are the mean value of 2 individual experiments. (B) Same cell lysates were separated by SDS-PAGE and transferred proteins were immunoblotted with anti-p70S6K.