Peptide/protein & many eicosanoid hormones act via Transmembrane (cell surface) receptors
Receptors for most peptide/protein as well as many eicosanoid hormones are embedded in the plasma membrane at the surface of the cell and the majority of these receptors belong to the G protein-coupled receptor (GPCR). The interaction of hormone and receptor typically triggers a cascade of secondary effects within the cytoplasm of the cell, described as signal transduction, often involving phosphorylation or dephosphorylation of various other cytoplasmic proteins, changes in ion channel permeability, or increased concentrations of intracellular molecules that may act as secondary messengers (e.g., cyclic AMP).
Some peptide/protein hormones also interact with intracellular receptors located in the cytoplasm or nucleus by an intracrine mechanism.
Follicle-stimulating hormone and receptor (GPCR Subfamily A10)
Adrenaline and Adrenergic receptors (GPCR Subfamily A17)
β1 adrenergic receptor
β2 adrenergic receptor
Neurotensin and receptor (GPCR class A)
Glucagon and receptor (GPCR Subfamily B1)
Glucagon-like peptide 1 receptor (GPCR Subfamily B1)
Glucose-dependent Insulinotropic Polypeptide Receptor (GPCR Subfamily B1)
Human growth hormone and receptor
Growth hormone receptor (GHR) is transmembrane protein consisting of 620 amino acids. GHR contains two fibronectin type III β domains in its extracellular domain, whereas the intracellular domain contains tyrosine Kinase JAK2 binding sites for SH2 proteins. JAK2 is the primary signal transducer for growth hormone. Prolactin receptor (PRLR) can also bind to and be activated by growth hormone.
Prolactin and receptor (Type I cytokine receptor)
Erythropoietin and receptor (Type I cytokine receptor)
Insulin and receptor (RTK class II)
Insulin-like Growth Factors and receptors (RTK)
Steroid & thyroid hormones act via Intracellular receptors (nuclear receptors)
For steroid or thyroid hormones, their receptors are located inside the cell within the cytoplasm of the target cell. These receptors belong to the nuclear receptor family of ligand-activated transcription factors. To bind their receptors, these hormones must first cross the cell membrane. They can do so because they are lipid-soluble. The combined hormone-receptor complex then moves across the nuclear membrane into the nucleus of the cell, where it binds to specific DNA sequences, regulating the expression of certain genes, and thereby increasing the levels of the proteins encoded by these genes.
However, it has been shown that not all steroid receptors are located inside the cell. Some are associated with the plasma membrane.
Thyroid Hormone Receptor-like
Thyroid hormone receptor
Estrogen Receptor-like
Estrogen receptor
Estrogen receptor alpha
Estrogen receptor beta
3-Ketosteroid receptors
Some eicosanoid hormones (prostanoids) also activate the PPARγ members of the steroid/thyroid family of nuclear hormone receptors
See also
