Graff JM, Bansal A, Melton DA. 1996. Xenopus Mad proteins transduce distinct subsets of signals for the TGF beta superfamily. Cell. 85(4):479-87. Pubmed: 8653784


Xenopus cDNAs homologous to the Drosophila Mad gene and C. elegans CEM genes have been cloned and functionally analyzed by microinjection into frog embryos. The results show that these genes (Xmad) encode intracellular proteins that act downstream of TGF beta superfamily ligands. Most interesting is the fact that different Xmad proteins produce distinct biological responses. Xmad1 produces ventral mesoderm, apparently transducing a signal for BMP2 and BMP4, whereas Xmad2 induces dorsal mesoderm like Vg1, activin, and nodal. These results suggest that an individual Xmad protein waits poised in the cytoplasm for instruction from a distinct subset of TGF beta ligands and then conveys specific information to the nucleus.

Related Faculty

Photo of Doug Melton

Doug Melton is pursuing a cure for type 1 diabetes. His lab studies the developmental biology of the pancreas, using that information to grow and develop pancreatic cells (islets of Langerhans). In parallel, they investigate ways to protect beta cells from autoimmune attack.

Search Menu