Transcriptional repression by the Caenorhabditis elegans germ-line protein PIE-1

Transcriptional repression by a Caenorhabditis elegans germ-line protein has been studied. In the early C. elegans embryo, PIE-1 protein, which is maternally expressed, is necessary in germ-line blastomeres to inhibit somatic differentiation, block phosphorylation of the RNA polymerase II large subunit (Pol II) carboxy-terminal domain (CTD) and maintain mRNA transcription absence. It has been found the PIE-1 can act as a transcriptional repressor in cell culture assays. A PIE-1 repression domain that seems to cut back transcriptional machinery directly has been identified. It seems repressor activity may be important for in vivo PIE-1 function.