Unr defines a novel class of nucleoplasmic reticulum involved in mRNA translation.

Unr (officially known as CSDE1) is a cytoplasmic RNA-binding protein with roles in the regulation of mRNA stability and translation. In this study, we identified a novel function for Unr, which acts as a positive regulator of placental development. Unr expression studies in the developing placenta revealed the presence of Unr-rich foci that are apparently located in the nuclei of trophoblast giant cells (TGCs).

The RNA-binding protein Unr prevents mouse embryonic stem cells differentiation toward the primitive endoderm lineage.

The maintenance of embryonic stem cells (ESCs) pluripotency depends on key transcription factors, chromatin remodeling proteins, and microRNAs. The roles of RNA-binding proteins are however poorly understood. We report that the cytoplasmic RNA-binding protein Unr prevents the differentiation of ESCs into primitive endoderm (PrE).