The THO complex regulates pluripotency gene mRNA export to control embryonic stem cell self-renewal and somatic cell reprogramming (RNA-IP)

Embryonic stem cell (ESC) self-renewal and differentiation is governed by a comprehensive regulatory network. Although the transcriptional regulation has been extensively investigated, post-transcriptional mechanisms controlling the ESC state are poorly understood. Here we describe a critical role of the THO complex in ESC self-renewal and differentiation. We show that THO preferentially interacts with pluripotency gene transcripts through Thoc5, and is required for self-renewal by regulating their export and expression. During differentiation, THO loses its interaction with those transcripts due to reduced Thoc5 expression, which leads to decreased expression of pluripotency proteins and facilitates differentiation. Finally, THO is also important for the establishment of pluripotency, as its depletion inhibits somatic cell reprogramming and blastocyst development. Together, our data indicates that THO regulates pluripotency gene mRNA export to control ESC self-renewal and differentiation, and uncovers a novel mechanism of post-transcriptional regulation in stem cell fate specification.