Spry1 is a member of the Sprouty (Spry) family proteins that was initially identified in Drosophila as an inhibitor of the FGF signaling pathway. There are four human Spry proteins (Spry1-4), encoded by different genes, and they all share a highly conserved carboxy-terminal cystine-rich Spry domain that is known to be essential for their receptor tyrosine kinase inhibitory function stimulated by various growth factors. Spry1 and other Spry proteins play a key role in embryonic development, tissue and organ formation, as well as growth in almost all living organisms. Spry proteins are considered tumor suppressors due to their inhibitory function in a variety of growth factor signaling pathways. Spry1 anchors itself to the membrane by palmitoylation and can translocate from the cytosol to the membrane by binding to caveolin-1. Regulation of Spry1 protein function is thought to occur at various levels. Spry1 regulation includes transcriptional regulation by growth factors and kinases, post-transcriptional regulation by microRNA-21, post-translational modifications including phosphorylation, dephosphorylation, ubiquitination and proteasomal degradation, and regulation by its interacting protein partners. |