Lisa S. Smit

Growth hormone receptor

Abstract The ability of growth hormone (GH) to stimulate body growth and regulate body metabolism results from GH binding to its cell surface receptor (GHR) in a variety of cell types. This review provides an overview of what is currently known about the GHR, including the cloning of the cDNA encoding GHR, identification of GHR as a member of the cytokine/hematopoietin receptor super-family, expression and regulation of GHR mRNA and protein, signaling pathways initiated by GH binding to GHR, and regions of GHR required for signal transduction. Signaling molecules, that have been implicated in GH action and are discussed in this review, include the GHR-associated JAK2 kinase, the SH2-containing adaptor molecules SHC and Grb2, the latent transcription factors, Stats 1, 3, and 5, the mitogen-activated protein kinases designated extracellular signal regulated kinases ERKs 1 and 2, the 90-kDa S6 kinase, the insulin receptor substrates (IRS) 1 and 2, phosphatidyl-inositol-3 (PI-3) kinase, diacylglycerol, protein kinase C, and calcium. These recent studies on GH receptors and actions have given us a new view of the way GH acts in the cell and have begun to provide insight into how GH elicits it diverse effects on body growth and metabolism via binding to its receptor.