Prospero homeobox protein 1 (Prox1) is transcription factor involved in developmental processes such as cell fate determination, gene transcriptional regulation and progenitor cell regulation in a number of organs [, ]. It is expressed in a subpopulation of endothelial cells that, after budding from veins, gives rise to the mammalian lymphatic system []. Prox1 has been found to be an early specific marker for the developing liver and pancreas in the mammalian foregut endoderm [].
Prospero-related proteins are conserved among metazoa and play important roles in development. They contain two characteristic conserved domains termed prospero domain 1 (PD1) and PD2 []. Drosophila Pros plays well-known roles in the establishment of cell fate during nervous system development []. In C. elegans, Prox1 functions as a major regulator of the glia-specific secretome that controls shape and function of sensory neurons []. Vertebrate Prox1 plays divergent roles in multiple organs by associating with nuclear receptors and modulating their transcriptional activities [, , ]. A second member of the family, Prox2, is present in vertebrates [, ].
