Connexon: Difference between revisions

Latest revision as of 06:41, 16 February 2025

Connexon[edit]

A connexon is a complex of six protein subunits called connexins that form a channel across the cell membrane. These channels are crucial components of gap junctions, which facilitate direct intercellular communication by allowing the passage of ions and small molecules between adjacent cells.

Structure[edit]

Connexons are hexameric assemblies of connexins, which are a family of structurally related transmembrane proteins. Each connexin subunit has four transmembrane domains, two extracellular loops, one intracellular loop, and cytoplasmic N- and C-termini. The connexins are arranged in a circular fashion to form a pore that spans the lipid bilayer of the cell membrane.

Function[edit]

Connexons play a critical role in maintaining homeostasis and enabling synchronized cellular activities. They allow the passage of ions, metabolites, and other small signaling molecules, which is essential for processes such as cardiac conduction, neuronal communication, and tissue homeostasis.

Assembly and Regulation[edit]

Connexons are assembled in the endoplasmic reticulum and Golgi apparatus before being transported to the cell membrane. The assembly and function of connexons are regulated by various factors, including phosphorylation, changes in pH, and calcium concentration. Connexons can dock with connexons from adjacent cells to form complete gap junction channels.

Clinical Significance[edit]

Mutations in connexin genes can lead to a variety of genetic disorders, such as Charcot-Marie-Tooth disease, nonsyndromic hearing loss, and certain types of skin disorders. Understanding the structure and function of connexons is crucial for developing therapeutic strategies for these conditions.

Related pages[edit]

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-'''Connexon'''
+{{DISPLAYTITLE:Connexon}}
-A '''connexon''' (also known as a '''connexin hemichannel''' or '''gap junction channel''') is an assembly of six proteins, called [[connexins]], that form a channel through the [[cell membrane]]. These channels allow for direct communication between the [[cytoplasm]] of adjacent cells, without the need for a signal to cross the extracellular space. This type of cell-cell communication is known as [[gap junction]] communication.
+== Connexon ==
-==Structure==
+[[File:Connexon_and_connexin_structure.svg|thumb|right|Diagram of connexon and connexin structure]]
-Each connexon is composed of six connexin proteins. These proteins are arranged in a circular fashion, creating a pore through the cell membrane. The connexin proteins themselves are four-pass transmembrane proteins, meaning they cross the cell membrane four times. The connexin proteins are named according to their molecular weight. For example, connexin 43 (Cx43) has a molecular weight of approximately 43 kilodaltons.
+A '''connexon''' is a complex of six [[protein]] subunits called [[connexin]]s that form a channel across the cell membrane. These channels are crucial components of [[gap junction]]s, which facilitate direct intercellular communication by allowing the passage of ions and small molecules between adjacent cells.
-==Function==
+== Structure ==
-Connexons form channels that allow for the direct transfer of small molecules and ions between cells. This includes molecules such as [[calcium ions]], [[cyclic AMP]], and [[inositol trisphosphate]]. These molecules are important for cell signaling and coordination of cellular activities.
+Connexons are hexameric assemblies of connexins, which are a family of structurally related transmembrane proteins. Each connexin subunit has four transmembrane domains, two extracellular loops, one intracellular loop, and cytoplasmic N- and C-termini. The connexins are arranged in a circular fashion to form a pore that spans the lipid bilayer of the cell membrane.
-Connexons can function in two ways: either as a hemichannel, allowing communication between the cell and the extracellular environment, or as a gap junction channel, allowing communication between two adjacent cells. When two connexons from adjacent cells align, they form a gap junction channel.
+== Function ==
-==Clinical significance==
+Connexons play a critical role in maintaining [[homeostasis]] and enabling synchronized cellular activities. They allow the passage of ions, metabolites, and other small signaling molecules, which is essential for processes such as [[cardiac conduction]], [[neuronal communication]], and [[tissue homeostasis]].
-Mutations in connexin genes can lead to a variety of diseases, known as [[gap junction diseases]]. These include skin disorders, deafness, cataracts, and cardiac abnormalities. For example, mutations in the gene for connexin 26 (Cx26) can lead to [[nonsyndromic deafness]].
+== Assembly and Regulation ==
-==See also==
+Connexons are assembled in the [[endoplasmic reticulum]] and [[Golgi apparatus]] before being transported to the cell membrane. The assembly and function of connexons are regulated by various factors, including [[phosphorylation]], changes in [[pH]], and [[calcium]] concentration. Connexons can dock with connexons from adjacent cells to form complete gap junction channels.
+== Clinical Significance ==
+Mutations in connexin genes can lead to a variety of [[genetic disorders]], such as [[Charcot-Marie-Tooth disease]], [[nonsyndromic hearing loss]], and certain types of [[skin disorders]]. Understanding the structure and function of connexons is crucial for developing therapeutic strategies for these conditions.
+== Related pages ==
 * [[Gap junction]]
+* [[Connexin]]
 * [[Cell membrane]]
-* [[Cell signaling]]
+* [[Intercellular communication]]
-==References==
-<references />
 [[Category:Cell biology]]
-[[Category:Membrane biology]]
+[[Category:Proteins]]
-[[Category:Protein complexes]]
-{{stub}}