Growth hormone receptor binding protein is produced either by proteolysis of the growth hormone receptor (GHR) at the cell surface thereby releasing its extracellular domain, the GHBP (growth hormone-binding protein), or, in rodents, by alternative processing of the GHR transcript. The sheddase proteolytic enzyme responsible for the cleavage is TACE (tumour necrosis factor-alpha-converting enzyme) [, ].Growth hormone (GH) binding to GH receptor is the initial step that leads to the physiological functions of the hormone []. The biological effects of GHBP are determined by the serum levels of GH, which can vary. Low levels of GH can result in a dwarf phenotype and have been positively correlated with an increased life expectancy. High levels of GH can lead to gigantism or a clinical syndrome termed acromegaly and have been implicated in diabetic eye and kidney damage [].
