Growth hormone binding protein. The soluble growth hormone receptor

Abstract

The high affinity growth hormone binding protein (GHBP), the soluble ectodomain of the growth hormone receptor (GHR), is an integral part of the growth hormone (GH)-insulin-like growth factor axis. Depending on the species, it is either a cleavage product of the GHR or a splice variant of the Ghr gene. GHR cleavage/GHBP shedding is effected by TACE (TNF-alpha converting enzyme), a metalloproteinase of the ADAM family, and possibly related enzymes. The GHBP modulates GH action through both inhibitory and enhancing mechanisms. Because of its complex in vivo effects, the biological role of the GHBP is still incompletely understood. The main clinical application of GHBP measurements is in the diagnosis of genetic growth hormone insensitivity (Laron syndrome).