Growth hormone (GH) signaling begins at the GH receptor, a cytokine-receptor family protein that recruits JAK2 and activates STAT transcription factors along with MAPK and PI3K-linked branches.
What it is
Growth hormone signaling refers to the intracellular events that follow GH binding to its receptor on target tissues such as liver, muscle, and adipose tissue. The pathway links endocrine GH pulses to gene programs involved in growth and metabolic regulation.
How it works
GH binding induces receptor dimer rearrangements that activate JAK2. Phosphorylated STAT5 and related STATs enter the nucleus to regulate target genes, including IGF-1 in hepatocytes.
Parallel MAPK and PI3K/AKT inputs broaden the response, so tissue outcomes depend on receptor density, feedback inhibitors such as SOCS proteins, and nutritional context.
Biological role
GH signaling contributes to postnatal growth, protein metabolism, and lipid handling. Educational pages often separate pituitary GH release from peripheral GH receptor signaling to keep mechanism maps clear.
Proteins involved
- Growth hormone receptor (GHR)
- JAK2
- STAT5
- SOCS2
- IGF-1 (downstream hepatic product)
Research summary
Decades of receptor biology describe JAK–STAT dependence, SOCS feedback, and tissue-specific transcriptional responses. Peptide research that alters GH secretion is related but not identical to direct GH receptor pharmacology.
Descriptions summarize published mechanistic frameworks. Findings from cell culture or animal models should not be interpreted as proven clinical effects in humans.
Research limitations
Scientific references
- Brooks AJ, Waters MJ. The growth hormone receptor: mechanism of activation and clinical implications. Nat Rev Endocrinol.
- Lanning NJ, Carter-Su C. Recent advances in GH signaling reviews.