Adiponectin (Acrp30)

Adiponectin, also known as Acrp30, is an adipocyte-derived protein with wide ranging paracrine and endocrine effects on metabolism and inflammation. It promotes adipocyte differentiation, fatty acid catabolism, and insulin sensitivity, and is negatively correlated with obesity, type 2 diabetes, and atherogenesis. In this context, adiponectin is an antiinflammatory agent, but it exerts proinflammatory effects in nonmetabolic disorders such as rheumatoid arthritis and inflammatory bowel disease. Adiponectin interacts with the receptors AdipoR1 and AdipoR2, calreticulin, and Cadherin13/ T-Cadherin, as well as with several growth factors. Mature mouse adiponectin consists of a 66 amino acid (aa) N-terminal collagenous region and a 137 aa C terminal C1q like globular domain which can be cleaved by a leukocytederived elastase. Mature mouse adiponectin shares 83% and 91% amino acid (aa) sequence identity with human and rat adiponectin, respectively. Adiponectin associates into trimers that may assemble into medium molecular weight (MMW) hexamers and then into >300 kDa high molecular weight (HMW) oligomers. The glycosylation of four hydroxylated lysine residues in the collagenous domain is required for the intracellular formation of HMW complexes. The various multimeric forms of adiponectin exhibit distinct tissue specific and gender specific profiles and activities.