New type of POU domain in germ line-specific protein Oct-4

Abstract

Members of a family of murine octamer-binding proteins inter-act specifically with the octamer motif, a transcription regulatory element found in the promoter and enhancer regions of many genes1. Oct-4 is a maternally expressed protein that is also present in the pre-implantation mouse embryo1,2. Although many regula-tory proteins are expressed in post-implantation embryos3, tran-scription factors regulating pre-implantation processes have remained elusive. The Oct-4 gene is therefore a ′ candidate for an early developmental control gene. Here we report the complementary DNA cloning of the mouse Oct-4 gene, and the characterization of the encoded protein(s) by sequential in vitro transcription, translation, DNA-binding and protease-clipping analysis. Deletion analysis shows that the DNA-binding activity is mediated by a POU domain encoded in an open reading frame corresponding to a 324-amino-acid protein4-13. Sequence com-parison with known POU domains reveals that Oct-4 is a novel member of the POU-family. © 1990 Nature Publishing Group.