Low Levels of Expression of Leptin Receptor at the Cell Surface Result from Constitutive Endocytosis and Intracellular Retention in the Biosynthetic Pathway

摘要: The leptin receptor is mainly localized in intracellular compartments target tissues. To study the mechanisms leading to this localization, two main isoforms of receptors, OB-Ra and OB-Rb, were expressed HeLa cells. Both at steady state trans-Golgi network, endosomes, a lesser extent, cell surface. They turned over with half-life less than 2 h. receptors constitutively endocytosed ligand-independent manner degraded lysosomes no evidence recycling surface or network. endocytosis was inhibited by deletion cytoplasmic domain. Newly synthesized partially retained Golgi complex post-Golgi compartment. transmembrane domain found be important for retention biosynthetic pathway, whereas not involved. data suggest that low levels expression results from partial coupled constitutive removal plasma membrane via ligand-independent, endocytosis.