Mutation in either the TSC1 or TSC2 tumor suppressor gene is responsible for the 
inherited genetic disease of tuberous sclerosis complex. TSC1 and TSC2 form a 
physical and functional complex to regulate cell growth. Recently, it has been 
demonstrated that TSC1.TSC2 functions to inhibit ribosomal S6 kinase and 
negatively regulate cell size. TSC2 is negatively regulated by Akt 
phosphorylation. Here, we report that TSC2, but not TSC1, associates with 14-3-3 
in vivo. Phosphorylation of Ser(1210) in TSC2 is required for its association 
with 14-3-3. Our data indicate that 14-3-3 association may inhibit the function 
of TSC2 and represents a possible mechanism of TSC2 regulation.