BMP and activin membrane-bound inhibitor (BAMBI) is a transmembrane glycoprotein that is a pseudoreceptor of type 1 receptors. BAMBI structurally lacks intracellular serine/ threonine kinase domain but with an extracellular domain and a short cytoplasmic region that share sequence similarities with type 1 receptors, whose members have functions in signal transduction in various developing and pathological processes. BAMBI competes with the type 1 receptor, a receptor of the transforming growth factor-beta (TGF-beta), through functioning as negative regulators of TGF-beta by limiting the signaling range of the TGF-beta family during early embryogenesis. The expression of BAMBI can be induced by accumulated beta-catenin and BMP. The expression level of BAMBI was found aberrantly elevated in most colorectal and hepatocellular carcinomas relative to the corresponding non-cancerous tissues. It suggestes that beta-catenin and TGF-beta interfere growth arrest by inducing the expression of BAMBI, and this may contribute to colorectal and hepatocellular tumorigenesis.
Sekiya T, et al. (2003) Identification of BMP and Activin Membrane-bound Inhibitor (BAMBI), an Inhibitor of Transforming Growth Factor- Signaling, as a Target of the -Catenin Pathway in Colorectal Tumor Cells. The Journal of Biological Chemistry. 279:6840-6. Shi YG, et al. (2003) Mechanisms of TGF- Signaling from Cell Membrane to the Nucleus. Cell. 113(6): 685-700. Wanninger J, et al. (2011) Adiponectin induces the transforming growth factor decoy receptor BAMBI in human hepatocytes. FEBS Lett. 585(9):1338-44.