Receptor-mediated nuclear translocation of growth hormone.

摘要: We have previously shown that the growth hormone (GH) receptor-binding protein is associated with nucleus. show here both by electron microscopy and nuclear isolation GH subject to rapid translocation. The intracellular fate of intravenously injected 125I-bovine (bGH) was examined in rat hepatocyte microscopic autoradiography. appeared rapidly at plasma membrane, then sequentially lysosomal multivesicular bodies and/or membrane before final translocation matrix. Maximal matrix occurred within 30 min injection. Nuclear 125I-hGH also studied nuclei from cells stably transfected cDNAs encoding receptor, GH-binding protein, a bound but cytoplasmic domain-deficient receptor. Specific internalization only full-length became saturated 1 h after addition culture media. SDS-polyacrylamide gel electrophoresis isolated showed transported nucleus as intact molecule. Pretreatment lysosomotropic agents (chloroquine, ammonium chloride, bacitracin) decreased degradation increased GH. achieved independent cytoskeletal system (microtubular, microfilament, intermediate filament networks). Thus, receptor-dependent via endosomal pathway.