title: TMEFF2 is an endogenous inhibitor of the CRH signal transduction pathway.
abstract: TMEFF2 is a transmembrane protein with unknown function, containing an altered epidermal growth factor (EGF)-like motif, two follistatin-like domains, and a cytosolic tail with a putative G-protein-activating motif. TMEFF2 is predominantly expressed in brain and prostate and has been implicated in cell signaling, neuronal cell survival, and tumor suppression. We found that expression of TMEFF2 in pituitary corticotrope cells inhibits the effects of corticotropin-releasing hormone (CRH) on the production of intracellular cAMP, and CREB, and transcription of Pomc. Regulation of the activity of CRH by TMEFF2 requires neither the cytoplasmic tail nor the EGF domain, while deletion of the follistatin modules abolishes the inhibitory function of TMEFF2. Moreover, a soluble secreted protein containing the complete extracellular domain is sufficient for inhibition of CRH signaling. TMEFF2-induced inhibition depends on serum components. Furthermore, TMEFF2 regulates the non-canonical activin/BMP4 signaling, PI3K, and Ras/ERK1/2 pathways. Thus, TMEFF2 inhibits the CRH signaling pathway and the PI3K/AKT and Ras/ERK1/2 pathways, contributing to a significant inhibition of transcription of Pomc. We found that expression of TMEFF2 in human Cushing's adenoma is reduced when compared with normal human pituitary, which may indicate that TMEFF2 acts as a tumor suppressor in these adenomas. Furthermore, the overexpression of TMEFF2 decreased proliferation of corticotrope cells. Our results indicate a potential therapeutic use of TMEFF2 or factors that stimulate the activity of TMEFF2 for the treatment of corticotrope tumors in order to reduce their secretion of ACTH and proliferation.
authors.affiliation: Department of NeuroendocrinologyMax Planck Institute of Psychiatry, 80804 Munich, Germany labeur@mpipsykl.mpg.de stalla@mpipsykl.mpg.de.
authors.forename: Marta
authors.initials: M
authors.lastname: Labeur
authors.affiliation: Department of NeuroendocrinologyMax Planck Institute of Psychiatry, 80804 Munich, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Wölfel
authors.affiliation: Department of NeuroendocrinologyMax Planck Institute of Psychiatry, 80804 Munich, Germany labeur@mpipsykl.mpg.de stalla@mpipsykl.mpg.de.
authors.forename: Johanna
authors.initials: J
authors.lastname: Stalla
authors.affiliation: Department of NeuroendocrinologyMax Planck Institute of Psychiatry, 80804 Munich, Germany.
authors.forename: Günter K
authors.initials: GK
authors.lastname: Stalla
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000818:Animals; D055415:Bone Morphogenetic Protein 4 / Q000502:physiology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D003346:Corticotropin-Releasing Hormone / Q000502:physiology*; D000242:Cyclic AMP / Q000378:metabolism; D006801:Humans; D020935:MAP Kinase Signaling System; D008565:Membrane Proteins / Q000502:physiology*; D051379:Mice; D009363:Neoplasm Proteins / Q000502:physiology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051381:Rats; D015290:Second Messenger Systems; D014158:Transcription, Genetic
chemical_list: C525809:BMP4 protein, human; D055415:Bone Morphogenetic Protein 4; D008565:Membrane Proteins; D009363:Neoplasm Proteins; C423567:TMEFF2 protein, human; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D000242:Cyclic AMP; D019869:Phosphatidylinositol 3-Kinases
keywords: CRH; Cushing's; POMC; TMEFF2