GRB10 Interacting GYF Protein 1 (GIGYF1)

The deduced 1,044-amino acid protein contains a GYF domain in its N-terminal half and a clathrin light chain homology domain in its C-terminal half. It also has a proline-rich region, multiple Q/E stretches, a consensus bipartite nuclear localization signal, several phosphorylation sites, and binding sites for protein phosphatase-1 , 14-3-3 proteins, and phospholipase C-gamma. Northern blot analysis detected Gigyf1 expression in all mouse tissues examined, with highest expression in brain and lung, followed by heart, spleen, and kidney.At later time points, Gigyf1 dissociated, but Grb10 remained linked to Igf1r. Overexpression of the Grb10-binding fragment of Gigyf1 resulted in a significant increase in Igf1-stimulated Igf1r tyrosine phosphorylation.