title: The transforming growth factor beta type II receptor can replace the activin type II receptor in inducing mesoderm.
abstract: The type II receptors for the polypeptide growth factors transforming growth factor beta (TGF-beta) and activin belong to a new family of predicted serine/threonine protein kinases. In Xenopus embryos, the biological effects of activin and TGF-beta 1 are strikingly different; activin induces a full range of mesodermal cell types in the animal cap assay, while TGF-beta 1 has no effects, presumably because of the lack of functional TGF-beta receptors. In order to assess the biological activities of exogenously added TGF-beta 1, RNA encoding the TGF-beta type II receptor was introduced into Xenopus embryos. In animal caps from these embryos, TGF-beta 1 and activin show similar potencies for induction of mesoderm-specific mRNAs, and both elicit the same types of mesodermal tissues. In addition, the response of animal caps to TGF-beta 1, as well as to activin, is blocked by a dominant inhibitory ras mutant, p21(Asn-17)Ha-ras. These results indicate that the activin and TGF-beta type II receptors can couple to similar signalling pathways and that the biological specificities of these growth factors lie in their different ligand-binding domains and in different competences of the responding cells.
authors.affiliation: Molecular Neurobiology Laboratory, Salk Institute, La Jolla, California 92037.
authors.forename: A
authors.initials: A
authors.lastname: Bhushan
authors.forename: H Y
authors.initials: HY
authors.lastname: Lin
authors.forename: H F
authors.initials: HF
authors.lastname: Lodish
authors.forename: C R
authors.initials: CR
authors.lastname: Kintner
mesh_terms: D029404:Activin Receptors; D028341:Activins; D000818:Animals; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000502:physiology*; D007265:Inhibins / Q000494:pharmacology*; D008648:Mesoderm / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000096:biosynthesis / Q000502:physiology*; D018125:Receptors, Transforming Growth Factor beta / Q000096:biosynthesis / Q000502:physiology*; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014982:Xenopus laevis / Q000196:embryology*
chemical_list: D017978:Receptors, Growth Factor; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D028341:Activins; D007265:Inhibins; D017346:Protein Serine-Threonine Kinases; D029404:Activin Receptors; D016283:Proto-Oncogene Proteins p21(ras)