A new class of genes containing small Open Reading Frames: cellular and molecular function of the encoded peptides. (360G-Wellcome-087516_Z_08_Z)

We have characterised a non-canonical gene, tarsal-less (tal). Tal is polycistronic and only contains small Open Reading Frames (smORFs) producing peptides as small as 11 amino-acids. These peptides function as a cell signal controlling gene expression and actin-mediated cell shape changes. I plan to ascertain the mechanisms for diffusion of these peptides and transmission of their signal by: A1) Investigating the mechanism of tal uptake in a cell culture assay; A2) Organising the proteins t hat bind tal (identified candidates and new ones to be searched for) in a pathway for the transmission of the signal; A3) Clarify the mechanism for tal-dependent transcriptional control; A3) Finding out how tal affects actin cytoskeleton. I also plan to search for more genes containing only smORFs in flies and other species, and to characterise a sample that will prove their existence as a class, and their general features, by: B1) searching for homologues of tal in distant species B2) characterising putative smORF genes we have already identified, to corroborate that their function is mediated by the small peptides they encode, and to obtain further information on their general structure and sequence signatures B3) searching for further smORF genes in flies, and finally in vertebrates