Is REST required for ESC pluripotency?

The DNA-binding protein REST (also called NRSF) is a transcriptional repressor that targets many neuronal genes and is abundant in human and mouse pluripotent embryonic stem cells (ESCs). In a recent Letter to Nature, Singh et al. suggested that REST controls the self-renewal and pluripotency of ESCs, because they found that ESCs in which a single REST allele was disrupted (Fig. 1a, beta-geo-stop insertion) had reduced alkaline phosphatase activity and expressed lower levels of several pluripotency-associated genes. Here we show that partial or complete loss of functional REST protein does not abrogate ESC potential as reflected by marker gene expression. These data are consistent with earlier reports, and argue that REST is not required for maintaining ESC pluripotency.