Somatotropin Protein (GH1) Human Active Protein

The protein encoded by this gene is a member of the somatotropin/prolactin family of hormones which play an important role in growth control. The gene, along with four other related genes, is located at the growth hormone locus on chromosome 17 where they are interspersed in the same transcriptional orientation; an arrangement which is thought to have evolved by a series of gene duplications. The five genes share a remarkably high degree of sequence identity. Alternative splicing generates additional isoforms of each of the five growth hormones, leading to further diversity and potential for specialization. This particular family member is expressed in the pituitary but not in placental tissue as is the case for the other four genes in the growth hormone locus. Mutations in or deletions of the gene lead to growth hormone deficiency and short stature. [provided by RefSeq, Jul 2008]

GH: Plays an important role in growth control. Its major role in stimulating body growth is to stimulate the liver and other tissues to secrete IGF-1. It stimulates both the differentiation and proliferation of myoblasts. It also stimulates amino acid uptake and protein synthesis in muscle and other tissues. Defects in GH1 are a cause of growth hormone deficiency isolated type 1A (IGHD1A); also known as pituitary dwarfism I. IGHD1A is an autosomal recessive deficiency of GH which causes short stature. IGHD1A patients have an absence of GH with severe dwarfism and often develop anti-GH antibodies when given exogenous GH. Defects in GH1 are a cause of growth hormone deficiency isolated type 1B (IGHD1B); also known as dwarfism of Sindh. IGHD1B is an autosomal recessive deficiency of GH which causes short stature. IGHD1B patients have low but detectable levels of GH. Dwarfism is less severe than in IGHD1A and patients usually respond well to exogenous GH. Defects in GH1 are the cause of Kowarski syndrome (KWKS); also known as pituitary dwarfism VI. Defects in GH1 are a cause of growth hormone deficiency isolated type 2 (IGHD2). IGHD2 is an autosomal dominant deficiency of GH which causes short stature. Clinical severity is variable. Patients have a positive response and immunologic tolerance to growth hormone therapy. Belongs to the somatotropin/prolactin family. 4 isoforms of the human protein are produced by alternative splicing.

Protein type: Hormone; Secreted; Secreted, signal peptide

Chromosomal Location of Human Ortholog: 17q23.3

Cellular Component: extracellular region; extracellular space

Molecular Function: growth factor activity; growth hormone receptor binding; prolactin receptor binding; protein binding

Biological Process: glucose transport; JAK-STAT cascade; positive regulation of insulin-like growth factor receptor signaling pathway; positive regulation of JAK-STAT cascade; positive regulation of MAP kinase activity; positive regulation of multicellular organism growth; positive regulation of peptidyl-tyrosine phosphorylation; positive regulation of phosphoinositide 3-kinase cascade; positive regulation of receptor internalization; positive regulation of tyrosine phosphorylation of STAT protein; response to estradiol stimulus

Disease: Isolated Growth Hormone Deficiency, Type Ia; Isolated Growth Hormone Deficiency, Type Ib; Isolated Growth Hormone Deficiency, Type Ii; Kowarski Syndrome