Cloning and expression of a human/mouse Polycomb group gene, ENX-2/Enx-2

The Drosophila Polycomb group (Pc-G) genes encode transcriptional factors involved in development. Little is known about members of the vertebrate Pc-G genes. In this study, we have isolated a cDNA encoding a human Pc-G protein and the mouse equivalent. The human and mouse genes, which were named ENX-2 and Enx-2, encode 702 and 750 amino acids, respectively. ENX-2/Enx-2 protein exhibits a high homology (53-55% identity) to Drosophila Enhancer of zeste [E(z)] protein belonging to the Pc-G. The expression of Enx-2 was observed in mouse kidney, adrenal gland, testis and brain at high levels by Northern blot analysis. A cell line of mouse neuroblastoma, Neuro-2a, also expresses Enx-2 mRNA and its level is elevated by induction of neuronal differentiation of the cell.