title: Interaction of insulin-like growth factor binding protein-3 with latent transforming growth factor-beta binding protein-1.
abstract: Insulin-like growth factor binding protein-3 (IGFBP-3) inhibits the replication and promotes apoptosis in various cell lines in an IGF-independent manner. We utilized a yeast two-hybrid system to identify binding partners for IGFBP-3 in a mouse embryo cDNA library. A partial cDNA encoding mouse latent transforming growth factor beta (TGF-beta) binding protein-1 (LTBP-1) was identified. This cDNA encoded a mouse LTBP-1 mRNA fragment corresponding to amino acid residues 1160-1712. Analysis of C-terminal deleted mutants indicated that the IGFBP-3 interacting domain resides in the 552 residue C-terminal fragment encoding amino acids 831-1383. The interaction of IGFBP-3 with recombinant human LTBP-1 immobilized on nitrocellulose was also demonstrated. Neither binding of IGF-1 to IGFBP-3 nor binding of latency associated protein (LAP) with LTBP-1 inhibited the interaction of IGFBP-3 with LTBP-1. Furthermore the large latent complex, 125I-TGF-beta/LAP/LTBP-1 was able to bind to immobilized IGFBP-3. These data demonstrate that IGFBP-3 can bind to LTBP-1 and provide a potential mechanism whereby IGFBP-3 can interact with the TGF-beta system.
authors.affiliation: Department of Physiology, University of Manitoba, Bannatyne Campus, Winnipeg, Canada.
authors.forename: Yaoting
authors.initials: Y
authors.lastname: Gui
authors.forename: Liam J
authors.initials: LJ
authors.lastname: Murphy
mesh_terms: D000818:Animals; D017209:Apoptosis; D002352:Carrier Proteins / Q000378:metabolism / Q000502:physiology*; D004247:DNA / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D017353:Gene Deletion; D015723:Gene Library; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D053779:Latent TGF-beta Binding Proteins; D008024:Ligands; D051379:Mice; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D018076:DNA, Complementary; D018972:Insulin-Like Growth Factor Binding Protein 3; D047908:Intracellular Signaling Peptides and Proteins; C509032:LTBP1 protein, human; D053779:Latent TGF-beta Binding Proteins; D008024:Ligands; C509033:Ltbp1 protein, mouse; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D004247:DNA; D001616:beta-Galactosidase