Leptin Receptor of Zucker Fatty Rat Performs Reduced Signal Transduction

Zucker fatty (fa/fa) rats exhibit overt obesity, hypercholesterolemia, hyperlipidemia, and hyperglycemia as recessive traits. The fa mutation has been determined to be a missense mutation in the extracellular domain of the leptin receptor. We report herein the construction of CHO cells that stably express the fa -type leptin receptor and the characterization of this receptor using mRNA expression levels of the immediate early genes, c-fos, c-jun , and jun-B , which are induced by leptin as a criterion of signal transduction. The fa -type receptor not only exhibits a slightly reduced leptinbinding affinity, but also performs reduced signal transduction.