Identification and characterization of the interaction between tuberin and 14-3-3zeta.
Tuberous sclerosis is caused by mutations to either the TSC1 or TSC2 tumor suppressor gene. The disease is characterized by a broad phenotypic spectrum that includes seizures, mental retardation, renal dysfunction, and dermatological abnormalities. TSC1 encodes a 130-kDa protein called hamartin, and TSC2 encodes a 200-kDa protein called tuberin. Although it has been shown that hamartin and tuberin form a complex and mediate phosphoinositide 3-kinase/Akt-dependent phosphorylation of the ribosomal protein S6, it is not yet clear how inactivation of either protein leads to tuberous sclerosis. Therefore, to obtain additional insight into tuberin and hamartin function, yeast two-hybrid screening experiments were performed to identify proteins that interact with tuberin. One of the proteins identified was 14-3-3zeta, a member of the 14-3-3 protein family. The interaction between tuberin and 14-3-3zeta was confirmed in vitro and by co-immunoprecipitation; multiple sites within tuberin for 14-3-3zeta binding were identified; and it was determined that 14-3-3zeta associated with the tuberin-hamartin complex. Finally, it was shown that the tuberin/14-3-3zeta interaction is regulated by Akt-mediated phosphorylation of tuberin, providing insight into how tuberin may regulate phosphorylation of S6.
Nellist
Mark
M
Department of Clinical Genetics, Erasmus Medisch Centrum, Dr. Molewaterplein 50, 3015 GE Rotterdam, The Netherlands. nellist@kgen.fgg.eur.nl
Goedbloed
Miriam A
MA
de Winter
Christa
C
Verhaaf
Brenda
B
Jankie
Anita
A
Reuser
Arnold J J
AJ
van den Ouweland
Ans M W
AM
van der Sluijs
Peter
P
Halley
Dicky J J
DJ
D048948:14-3-3 Proteins; D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D006367:HeLa Cells; D006801:Humans; D008957:Models, Genetic; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D011233:Precipitin Tests; D011485:Protein Binding; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry* / Q000378:metabolism; D038601:Ribosomal Protein S6 / Q000378:metabolism; D014162:Transfection; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins; D020798:Two-Hybrid System Techniques; D014446:Tyrosine 3-Monooxygenase / Q000737:chemistry* / Q000378:metabolism
D048948:14-3-3 Proteins; D020033:Protein Isoforms; D012097:Repressor Proteins; D038601:Ribosomal Protein S6; C000624653:TSC2 protein, human; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins; D014446:Tyrosine 3-Monooxygenase; D019869:Phosphatidylinositol 3-Kinases