Characterization of the interaction of FKBP12 with the transforming growth factor-beta type I receptor in vivo.
The type I transforming growth factor-beta receptor (TbetaR-I) is the efferent component of the receptor complex, which presumably phosphorylates intracellular targets. FKBP12, a binding protein for FK506 and rapamycin, is shown to associate with the cytoplasmic region of TbetaR-I in vitro. In this report, we investigated the interaction of FKBP12 with TbetaR-I in vivo. FKBP12 interacts with TbetaR-I in mammalian cells as well as in yeast. Ligand addition does not affect the interaction, and both constitutively active and kinase-negative mutants of TbetaR-I bind FKBP12. FKBP12 dissociates from TbetaR-I in the presence of a high concentration of FK506. The juxtamembrane region of TbetaR-I, containing the major phosphorylation sites by the type II receptor, is required for the interaction. One of the deletion mutants in this region, which was shown to mediate transcriptional response, does not bind FKBP12, suggesting that FKBP12 is not directly involved in TGF-beta signaling. Furthermore TbetaR-I does not phosphorylate FKBP12 in vitro. FKBP12 may not be a direct substrate of TbetaR-I but possibly modulates the TbetaR-I function through its interaction with the regulatory domain of the kinase.
Okadome
T
T
Department of Biochemistry, The Cancer Institute, Tokyo, Japanese Foundation for Cancer Research, 1-37-1 Kami-Ikebukuro, Toshima-ku, Tokyo 170, Japan.
Oeda
E
E
Saitoh
M
M
Ichijo
H
H
Moses
H L
HL
Miyazono
K
K
Kawabata
M
M
D030201:Activin Receptors, Type I; D019883:Alkyl and Aryl Transferases; D000591:Amino Acid Isomerases / Q000378:metabolism*; D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005784:Gene Amplification; D006367:HeLa Cells; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D010766:Phosphorylation; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism*; D016559:Tacrolimus / Q000494:pharmacology; D022021:Tacrolimus Binding Proteins; D014166:Transferases / Q000378:metabolism
D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D006360:Heat-Shock Proteins; D018125:Receptors, Transforming Growth Factor beta; D014166:Transferases; D019883:Alkyl and Aryl Transferases; C064911:p21(ras) farnesyl-protein transferase; D017346:Protein Serine-Threonine Kinases; D030201:Activin Receptors, Type I; D000077293:Receptor, Transforming Growth Factor-beta Type I; D000591:Amino Acid Isomerases; D022021:Tacrolimus Binding Proteins; D016559:Tacrolimus