Zinc Finger Protein 717 (ZNF717)

ZNF717, a KRAB-ZNF of unknown function, serves as a bridge node between the two portions of the network, tied by positive links to Module 2 and negative links to Module 1. It is tempting to speculate that these negatively linked TFs constitute direct repressive targets of ZNF717, a hypothesis that can now be tested experimentally.

Like several other KRAB-ZNFs in this network, ZNF717 is a primate-specific duplicate, with an ortholog in chimpanzee and orangutan but not in rhesus macaque (as determined by reciprocal BLAST and investigation of synthetic genomic region); its predicted role as a connector between the two modules would therefore represent a very recent evolutionary change. In addition, some TFs stand out for striking species-specific differences in the number and identity of their network links.