The adiponectin receptors, ADIPOR1 and ADIPOR2, serve as receptors for globular and full-length adiponectin and mediate increased AMPK and PPAR-alpha (PPARA) ligand activities, as well as fatty acid oxidation and glucose uptake by adiponectin. ADIPOR1 and ADIPOR2 are highly related structurally, and mouse Adipor1 and Adipor2 share 66.7% identity. ADIPOR1 and ADIPOR2 are 7-transmembrane domain proteins, but they are structurally, topologically, and functionally distinct from G proteincoupled receptors (GPCRs). The mouse, human, and rat Adipor1 protein (ADIPOR1) contains 375 amino acids (with a predicted MW of 42.4 kD). Human and mouse ADIPOR1 have 96.8% homology. ADIPOR1 has high-affinity receptor for globular adiponectin (gACRP30) but low-affinity receptor for full-length adiponectin. ADIPOR1 is widely expressed. It is highly expressed in skeletal muscle. It is expressed at intermediate levels in brain, heart, spleen, kidney, liver, placenta, lung and peripheral blood leukocytes. It is weakly expressed in colon, thymus and small intestine.