N-Myc Interactor, also known as NMI, is a protein that belongs to the oncogene Myc family. This family of oncogenes plays a crucial role in cell proliferation, differentiation, and neoplastic transformation . NMI was first characterized as an interactor of c-Myc and N-Myc using a yeast two-hybrid screen . Since its discovery, NMI has been extensively studied for its roles in cancer progression and viral pathologies .
The human NMI gene is located on chromosome 2q23 and contains three exons that can form four alternatively spliced mRNA transcripts . Expression profiling has shown that NMI is expressed in all fetal tissues except the brain and is primarily found in the adult spleen, liver, and kidneys . The protein is largely cytoplasmic, although it has been detected in the nucleus in multiple studies .
NMI is a 38 kDa protein that acts as an adapter molecule with different functions depending on the cellular context . It has several functional domains:
NMI interacts with all STATs (Signal Transducer and Activator of Transcription) except STAT2 and enhances STAT-mediated transcription in response to cytokines such as interleukin 2 (IL2) and interferon-gamma (IFN-gamma) . This interaction is crucial for the transcription of downstream genes involved in various signaling pathways for development and homeostasis .