RUI: The Role of APH-1 and APH-2 in Notch-Mediated Cell Interactions in C. Elegans

Amherst College, Amherst MA

Investigators

Abstract

Abstract for Proposal #0131657 Caroline Goutte The Notch signaling pathway represents a conserved mechanism of cell communication. During the development of C. elegans there are multiple events in which the Notch signaling pathway plays a critical role in cell fate induction. Our work focuses on two newly identified components of Notch signaling events, the C. elegans aph-1 and aph-2 gene products. Previous work has shown that the aph-1 and aph-2 genes encode novel proteins that are well conserved in other systems, including humans; however, their function in Notch signaling events remains unknown. The primary objective of this proposal is to examine the roles of the APH-1 and APH-2 proteins in facilitating cell-cell interactions. To this end three general areas of investigation will be pursued. First, a series of experiments will be carried out to delineate where in the Notch signaling pathway the APH-1 and APH-2 proteins function. Which cells require APH-1 and APH-2 activity, and is their function required before or after receptor interaction with its ligand? The methods will include analysis of APH-1 cellular and subcellular expression patterns, manipulation of individual embryonic cells, and genetic epistasis analysis. Second, we will use standard mapping and cloning procedures to pursue the molecular identity of four new genes that were previously isolated as genetic suppressors of an aph-1 mutation. Because mutations in these genes can compensate for defective APH-1 activity, elucidation of their molecular identity will shed light on the normal function of APH-1, as well as identify potential new players of Notch-mediated events. Third, an exploration into post-embryonic roles for APH-1 and APH-2 will be initiated by examining post-embryonic mutant phenotypes, genetic interactions with other Notch pathway components, and an analysis of post-embryonic APH-1 expression patterns. Because APH-1 and APH-2 are found in other systems, it is expected that results from this study will contribute to the general understanding of Notch signaling in all species.