[
International Worm Meeting,
2017]
Transforming Growth Factor-beta (TGF- beta ) is a family of secreted cell signaling ligands. DBL-1, TGF- beta superfamily member in the roundworm C. elegans, is secreted from nervous tissue, but must be received by receptors in neighboring cells to regulate body size, secretion of specialized extracellular matrix (surface barrier), and other processes. The control of TGF- beta within the secreting cells is not well known in any system. We are using the C. elegans model system to identify new regulators involved in this conserved signaling pathway. For that, we are using two approaches to identify TGF- beta regulators. First, we used a C. elegans strain expressing GFP-tagged DBL-1 in an RNA interference (RNAi) screen to determine candidates involved in the regulation for this pathway. We knocked down candidate genes by RNAi and assayed changes in GFP-tagged DBL-1 fluorescence intensity within the ventral nerve cord. We then asked if the candidate gene products found with this screening co-localized with GFP-tagged DBL-1. Our results show in vivo the implication of a novel protein secretory pathway for DBL-1 transport. Second, we are performing co-immunoprecipitation using GFP-tagged DBL-1 as a bait to identify the different proteins that directly bind DBL-1. Together, this work is expected to identify proteins that interact with DBL-1 and regulate it within the secreting cell and in the extracellular milieu between DBL-1-secreting and receiving cells.