Mutation of GLP-1/Notch RAM domain results in a strong Glp-1 phenotype.

The distal tip cell niche uses GLP-1 /Notch signaling to maintain germline stem cells. The RAM domain, which resides within the intracellular portion of the GLP-1 /Notch receptor, is integral to formation of a signaling-dependent transcription activation complex. Here we report the generation of a mutation in the GLP-1 RAM domain, created in a GLP-1 /Notch receptor with a C-terminal V5 tag. The phenotype of homozygotes is similar to that of null mutants, but expression of the GLP-1 (RAM ) protein was normal in the heterozygotes. We conclude that the RAM mutation abolishes receptor activity.