| Using yeast two hybrid screening , the N terminus of Grb 10 was shown to interact with two novel proteins , designated GIGYF 1 ( Grb 10 interacting GYF protein 1 ) and GIGYF 2 . ^^^ Mutation analysis indicates that a 17 amino acid sequence in GIGYF 1 and GIGYF 2 , homologous to the GYF domain described previously , binds to tandem proline rich regions in the N terminus of Grb 10 . ^^^ |