| Cell migration is an important process that is essential for embryonic development and tissue and organ morphogenesis in all animals. CACN-1/Cactin is a novel and well-conserved gene that is required for distal tip cell migration and gonad morphogenesis in the C. elegans nematode worm. Previous studies have identified proteins that interact in complexes to control cell behaviors such as cell migration. In our study, we conducted a genome wide yeast two-hybrid screen to identify specific proteins that interact with CACN-1 in vivo. CACN-1 interacting proteins were first identified based on growth on auxotrophic media and were subsequently isolated, validated, and sequenced using reporter gene activation assays and DNA sequencing. Among the 28 different genes identified in the screen, MIG-5/Dishevelled was confirmed to be a novel molecular partner of CACN-1 using an in vitro GST pull-down. The verified biochemical interaction of CACN-1 with MIG-5 suggests CACN-1 may have a role in the Wnt signaling pathway, and more specifically, may be influencing Wnt signaling by directly interacting with MIG-5. In addition, RNAi depletion experiments and analysis of the two mutant alleles of mig-5 (rh94 and rh147) suggest that, like CACN-1, MIG-5 is required for the control of proper DTC migration. Because both CACN-1 and MIG-5 are conserved proteins that have been genetically or biochemically linked to Rac GTPase signaling, results from this study will be important in improving our understanding of the fundamental regulation of cell migration during animal development, and will provide significant insights into the mechanisms by which CACN-1 regulates cell migration. |
