Novel mode of JAK-STAT pathway regulation Available to Purchase

By adapting a technique that assays receptor dimerization in vitro for use in whole Drosophila embryos, Brown et al., on p. 3077, have discovered a novel level of JAK/STAT signalling regulation. The authors tackled the question of whether the JAK/STAT pathway is activated by ligand-induced receptor dimerization by studying DOME, the ubiquitously expressed fly receptor of the JAK/STAT pathway. They report that in developing fly embryos,DOME homo-dimerization is developmentally regulated and is not ligand induced. Moreover, ligand expression can only activate the pathway or affect embryonic development in cells with dimerized receptors. Thus, the ability to induce JAK/STAT signalling can be regulated by controlling receptor dimerization prior to ligand binding. As this pathway in flies is functionally identical to that in vertebrates, this regulatory mechanism could be conserved across phyla.