TIAF1 participates in the transforming growth factor beta1--mediated growth regulation.
TGF-beta induces growth suppression and apoptosis of various types of cells, but supports fibroblast growth. We previously isolated TIAF1 (TGF-beta1-induced antiapoptotic factor 1), which protects murine L929 fibroblasts from TNF cytotoxicity. Here, we show that TIAF1 induced growth inhibition and apoptosis of monocytic U937 and other types of cells. In contrast, like TGF-beta1, TIAF1 supported transforming growth of L929 fibroblasts. TIAF1 increased the expression of p53, Cip1/p21, and Smad proteins; suppressed ERK phosphorylation; and altered TGF-beta1-mediated Smad2/3 phosphorylation in U937 cells. Antisense TIAF1 mRNA significantly enhanced the proliferation of mink lung Mv1Lu epithelial cells. Together, these observations indicate that TIAF1 participates in the TGF-beta-mediated growth regulation.
Khera
Smaira
S
Laboratory of Molecular Immunology, Guthrie Research Institute, Sayre, Pennsylvania 18840, USA.
Chang
Nan-Shan
NS
D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins / Q000502:physiology*; D002455:Cell Division; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D004268:DNA-Binding Proteins / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology; D018922:HL-60 Cells; D006801:Humans; D051379:Mice; D018995:Myosin Heavy Chains; D009369:Neoplasms / Q000378:metabolism / Q000473:pathology; D009687:Nuclear Proteins; D015398:Signal Transduction; D051899:Smad2 Protein; D051901:Smad4 Protein; D015534:Trans-Activators / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000494:pharmacology / Q000502:physiology*; D053773:Transforming Growth Factor beta1; D014407:Tumor Cells, Cultured; D020298:U937 Cells; D009218:Myosins
D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D018995:Myosin Heavy Chains; D009687:Nuclear Proteins; D051899:Smad2 Protein; D051901:Smad4 Protein; D015534:Trans-Activators; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C497782:SMAD2 protein, human; C497796:SMAD4 protein, human; C497783:Smad2 protein, mouse; C490810:Smad4 protein, mouse; C508960:TGFB1 protein, human; C407152:MYO18A protein, human; D009218:Myosins; C508961:Tgfb1 protein, mouse