Transforming growth factor beta receptor

Transforming growth factor beta receptor (TGF-beta receptor) is a type of cell surface receptor that binds and responds to the transforming growth factor beta (TGF-beta), a multifunctional protein that regulates many aspects of cellular function, including cell growth, cell differentiation, apoptosis, and cell migration.

Structure

The TGF-beta receptor is a complex of two types of serine/threonine kinase receptors, known as type I and type II. Both types are transmembrane proteins with a cysteine-rich extracellular domain for ligand binding, a single transmembrane domain, and an intracellular domain with serine/threonine kinase activity.

Function

The primary function of the TGF-beta receptor is to transduce the TGF-beta signal from the cell surface to the interior of the cell. This is achieved through a process known as signal transduction, which involves a series of biochemical reactions that ultimately lead to a change in cell function.

When TGF-beta binds to the type II receptor, it causes the recruitment and activation of the type I receptor. The activated type I receptor then phosphorylates Smad proteins, which form a complex with Smad4 and translocate to the nucleus. In the nucleus, the Smad complex regulates the transcription of target genes, leading to changes in cell function.

Clinical significance

Mutations in the TGF-beta receptor can lead to various diseases. For example, mutations in the type II receptor are associated with Marfan syndrome, Loeys-Dietz syndrome, and familial thoracic aortic aneurysm and dissection. Mutations in the type I receptor are associated with Camurati-Engelmann disease.

In addition, the TGF-beta receptor plays a key role in cancer. Overexpression of the receptor can lead to increased TGF-beta signaling, which can promote tumor growth and metastasis. Conversely, loss of receptor function can lead to decreased TGF-beta signaling, which can result in uncontrolled cell growth and cancer.

See also

• Transforming growth factor beta
• Cell surface receptor
• Signal transduction
• Smad proteins