NRAC (Nutritionally Regulated Adipose and Cardiac enriched protein, with the human homologous gene designated as C14ORF180) is a recently identified adipocyte-specific double-pass transmembrane protein. Both its N- and C-termini are located intracellularly, containing only a short extracellular loop and no known enzymatic domains. Its expression is significantly induced during the differentiation of white and brown adipocytes and is regulated by nutritional status: fasting and obesity both downregulate its mRNA levels, suggesting its role as a "fat sensor" in energy homeostasis. Mechanistically, NRAC forms a trimeric complex via its first transmembrane domain with the fatty acid transporter core protein CD36 and the membrane microdomain protein caveolin-1. When extracellular fatty acid concentrations increase, NRAC undergoes ubiquitination and internalization, causing CD36 to dissociate from caveolin-1 and switch to clathrin-mediated endocytosis. This process enhances fatty acid uptake, leading to adipocyte hypertrophy and increased overall adipose mass.