Molecular biology of growth hormone receptors

Growth hormone (GH), synthesized in and secreted from the anterior pituitary lobe, has multiple effects at both the cellular and the organismal levels, including promotion of body growth, stimulation of intermediary metabolism, and transcriptional regulation of specific genes. These effects are believed to be mediated by high-affinity cell-surface receptors, which have recently been cloned and characterized and found to be members of a newly described receptor family. Although GH receptor expression is widespread, the cellular mechanisms by which GH binding to those receptors initiates cellular responses are still unclear. Functional expression of the cloned receptor in tissue culture has resulted in substantial progress toward that goal.