Hedgehog signal transduction proteins: contacts of the Fused kinase and Ci transcription factor with the Kinesin-related protein Costal2
1 Laboratoire de génétique et évolution, Institut Jacques Monod, 2 Place Jussieu, 75005 ,Paris, France
2 Departments of Developmental Biology and Genetics, Howard Hughes Medical Institute, 279 Campus Drive, Stanford University, School of Medicine, Stanford, California, USA
BMC Developmental Biology 2002, 2:4 doi:10.1186/1471-213X-2-4Published: 19 March 2002
Hedgehog signaling proteins play important roles in development by controlling growth and patterning in various animals including Drosophila and mammals. Hedgehog signaling triggers changes in responsive cells through a novel transduction mechanism that ultimately controls the transcription of specific target genes via the activity of zinc finger transcription factors of the Cubitus interruptus /GLI family. In flies, key Hedgehog signal transduction components have been identified including the kinesin-related protein Costal2, the serinethreonine kinase Fused, and the PEST-containing protein Suppressor of Fused. These proteins control Cubitus interruptus cleavage, nucleo-cytoplasmic localization and activation. In fly embryos, Costal2, Fused, Suppressor of Fused and Cubitus interruptus are associated in at least one cytoplasmic complex, which interacts with the microtubules in a Hedgehog-dependent manner.
Here we identified and mapped direct interactions between Cos2, Fu, and Ci using an in vitro affinity assay and the yeast two-hybrid system.
Our results provide new insights into the possible mechanism of the cytosolic steps of Hedgehog transduction.