Enzyme-linked receptor

Enzyme-linked receptors (also known as enzyme-coupled receptors) are a group of proteins that are located in the cell membrane. They are a type of cell surface receptor that activate an intracellular enzyme cascade when stimulated by a ligand (a molecule that binds to another).

Structure

Enzyme-linked receptors are composed of an extracellular domain, a transmembrane domain, and an intracellular domain. The extracellular domain is the part of the receptor that binds to the ligand. The transmembrane domain anchors the receptor in the cell membrane. The intracellular domain can have various functions, but often it has enzymatic activity or it is associated with an enzyme.

Function

When a ligand binds to the extracellular domain of an enzyme-linked receptor, it causes a change in the receptor's shape. This change activates the intracellular domain, which then triggers a series of reactions inside the cell. These reactions can lead to various cellular responses, such as cell growth, differentiation, or death.

Types

There are several types of enzyme-linked receptors, including:

• Receptor tyrosine kinases (RTKs)
• Serine/threonine-specific protein kinases
• Guanylate cyclase receptors
• Receptor-like tyrosine phosphatases
• Histidine kinase receptors

Each of these types of receptors has a different function and is involved in different cellular processes.

Clinical significance

Enzyme-linked receptors play a crucial role in many biological processes, and their malfunction can lead to various diseases. For example, overactivity of certain receptor tyrosine kinases is associated with cancer. In addition, mutations in the genes encoding these receptors can cause genetic disorders.

See also

• G protein-coupled receptor
• Ion channel-linked receptor
• Intracellular receptor