Transcriptional regulator that acts as a negative regulator of receptor-dependent signaling pathways (By similarity). Specifically inhibits transactivation of the nuclear receptor with which it interacts (By similarity). Inhibits transcriptional activity of NEUROD1 on E-box-containing promoter by interfering with the coactivation function of the p300/CBP-mediated transcription complex for NEUROD1 (PubMed:14752053). Essential component of the liver circadian clock which via its interaction with NR1D1 and RORG regulates NPAS2-mediated hepatic lipid metabolism (By similarity). Regulates the circadian expression of cytochrome P450 (CYP) enzymes (By similarity). Represses: NR5A2 and HNF4A to down-regulate CYP2C38, NFLI3 to up-regulate CYP2A5, BHLHE41/HNF1A axis to up-regulate CYP1A2, CYP2E1 and CYP3A11, and NR1D1 to up-regulate CYP2B10, CYP4A10 and CYP4A14 (By similarity). Interacts (via N-terminus) with NEUROD1 (via N-terminus and C-terminus) (PubMed:14752053). Interacts with ID2 (PubMed:14752053). Interacts with RORG, NFIL3, NR1D1 and BHLHE41 (By similarity). Heterodimer; efficient DNA binding requires dimerization with another bHLH protein (PubMed:14752053). Interacts with RARA, RXRA, THRB, NR5A1, NR5A2, NR1I3, PPARA, PPARG and EID1 (By similarity). Interacts with HNF4A; the resulting heterodimer is transcriptionnally inactive (PubMed:28128295). Interacts with DDX3X; this interaction disrupts the interaction between HNF4 and NR0B2/SHP that forms inactive heterodimers and enhances the formation of active HNF4 homodimers (PubMed:28128295). Colocalizes with NEUROD1 in the nucleus. Liver. Low levels of expression were detected in heart and pancreas. Arginine methylation by PRMT5 enhances repression activity of metabolic genes in liver in response to bile acid signaling, by increasing interaction with cofactors. Disease susceptibility is associated with variants affecting the gene represented in this entry. Belongs to the nuclear hormone receptor family. NR0 subfamily.