Activin signal transduction pathways

Many of the signal transduction pathways required for mammalian endocrine c el function are conserved from flies and worms. These model organisms permi tted the illumination of the biological properties of ligands and provided systems in which cellular coactivating molecules could be identified rapidl y. Our knowledge about the activin signaling components has been advanced t remendously by the work carried out in these systems. Subsequent research i s beginning to reveal the complex interactions that serve to regulate this signaling pathway.