Review Crim1–, a regulator of developmental organogenesis

availability and activity is critical during embryogenesis to ensure appropriate organogenesis. This process is regulated through the coordinated expression of growth factors and their cognate receptors, as well as via proteins that can bind, sequester or localize growth factors to distinct locations. One such protein is the transmembrane protein Crim1. This protein has been shown to be expressed broadly within the developing embryo, and to regulate organogenesis within the eye, kidney and placenta. Mechanistically, Crim1 has been revealed to mediate organogenesis via its interaction with growth factors including TGFβs, BMPs, VEGFs and PDFGs. More recently, Crim1 has been shown to influence cardiac development, providing further insights into the function of this protein. This review will provide an overview of the role of Crim1 in organogenesis, largely focusing on how this protein regulates growth factor signaling in the nascent heart. Moreover, we will address the challenges ahead relating to further elucidating how Crim1 functions during development.