Connexin

Connexin is a type of protein that forms gap junctions, which are channels that allow for communication between cells. Connexins are crucial for many physiological processes, including the transmission of electrical signals in the heart and the development of the nervous system.

Structure

Connexins are made up of four transmembrane domains, two extracellular loops, a cytoplasmic loop, and cytoplasmic N- and C-termini. The arrangement of these components allows for the formation of a pore through which ions and small molecules can pass.

Function

Connexins form gap junctions, which are channels that allow for direct communication between the cytoplasm of adjacent cells. This communication is crucial for many physiological processes, including the transmission of electrical signals in the heart and the development of the nervous system.

Types

There are 21 known types of connexins in humans, each encoded by a different gene. These include Connexin 26, Connexin 32, and Connexin 43, among others. Each type of connexin can form a gap junction on its own, or it can combine with other types to form a heteromeric gap junction.

Role in Disease

Mutations in connexin genes can lead to a variety of diseases, including deafness, skin disorders, and heart disease. For example, mutations in the gene for Connexin 26 are the most common cause of non-syndromic deafness.

See Also

• Gap junction
• Connexin 26
• Connexin 32
• Connexin 43

References

• Connexin
  Connexin
• Connexon and connexin structure
  Connexon and connexin structure
• Life cycle and protein associations of connexins
  Life cycle and protein associations of connexins