14-3-3 tau associates with a translational control factor FKBP12-rapamycin-associated protein in T-cells after stimulation by pervanadate

Proteins of the 14-3-3 family can associate with and/or modulate the activi ties of a variety of proteins, such as protooncogene and oncogene products, Cdc25 phosphatases and phosphatidylinositol 3-kinase, and thus are implica ted in regulation of signaling pathways and the cell cycle. We report here that treatment of Jurkat T-cells with an inhibitor of protein tyrosine phos phatase, pervanadate, induces the association of 14-3-3 tau with a translat ional control factor, FKBP12-rapamycin-associated protein (FRAP), with sign ificant latter's autophosphorylation. Coimmunoprecipitation of various muta nts of FRAP coexpressed with 14-3-3 tau in COS-7 cells revealed that 14-3-3 tau binds to the C-terminal side of FRAP at unknown site(s) different from the predicted binding motifs to date. (C) 2000 Federation of European Bioc hemical Societies.