Fig. 2From: STAT3 phosphorylation in central leptin resistanceSchematic representation of leptin receptors isoforms. Six different spliced isoforms of the leptin receptors (LepR) have been documented as LepRa–LepRf. All the isoforms share identical extracellular ligand-binding domain formed from the second segment of cytokine receptor homology (CRH) and fibronectin type III domain (FN3). LepRs presents a variable-length cytoplasmic portion (except the soluble receptor LepRe). LepRb, the long form of the receptor, is the only isoform that contains three tyrosine conserved regions (Y985, Y1077, and Y1138) enabling the leptin-induced activation of the JAK-STAT pathway. Box1 and Box2 are involved in JAK association and activation. Ig, immunoglobulin domain; JAK, Janus kinaseBack to article page