TUB (TUB bipartite transcription factor) is a membrane-associated signaling protein that functions as a bridge between G protein-coupled receptor signaling and transcriptional regulation. The protein contains a characteristic carboxy-terminal tubby domain that selectively binds phosphoinositides at cell membranes, enabling signal transduction from activated GPCRs 1. TUB localizes to multiple cellular compartments including the cytoplasm, nucleus, and primary cilia, where it participates in intraciliary transport 1. In the hypothalamus, TUB is expressed in multiple nuclei involved in body weight regulation, including the paraventricular and supraoptic nuclei 2. TUB regulates the TCR-phospholipase C gamma signaling axis to control NAMPT expression, which is critical for NAD+ synthesis and T cell activation 3. Additionally, TUB functions in the lithocholic acid-TULP3-sirtuin-v-ATPase-AMPK pathway that activates energy metabolism and extends lifespan 4. Clinically, TUB mutations cause maturity-onset obesity and insulin resistance 1, with reduced adipose tissue TUB expression correlating with obesity severity in humans 2. The protein also contributes to retinal function and immune homeostasis, making it relevant to retinal dystrophy and metabolic disease pathogenesis.