Dose-resolved control of somatic reprogramming by Rora

Nuclear receptors (NRs) are ligand-regulated transcription factors whose domains and dosage modulate gene networks. We systematically profiled 49 murine NRs in OKS (OCT4/KLF4/SOX2) reprogramming of mouse fibroblasts and identified the ROR subfamily as enhancers. Focusing on Rora, we uncovered a dose-dependent, biphasic effect on reprogramming: moderate Rora increases OCT4-GFP⁺ colony formation, whereas higher expression reduces colonies. Domain dissection separated these arms-DNA-binding domain (DBD)/ligand-binding domain (LBD) was required for the pro-reprogramming effect, while the N-terminal domain (NTD) was required for high-dose inhibition (ΔNTD eliminated the inhibitory limb). Functionally, the reprogramming barrier interferon (IFN)-γ was attenuated at transcript and protein levels; IFN-γ add-back dampened the enhancement, supporting immune-axis modulation. Conversely, WNT pathway output was reduced in the inhibitory arm, and CHIR99021 partially rescued the high-dose colony defect. Thus, RORA acts as a dose-programmed, domain-modular regulator that coordinates chromatin and signaling to gate cell-fate conversion, establishing nuclear-receptor dosage control as a lever to improve reprogramming efficiency.