What is gap junction protein connexin 43?
What is gap junction protein connexin 43?
Gap junctions are transmembrane complexes of connexin proteins that allow intercellular communication and the transfer of ions and small signaling molecules between adjacent cells1. In mice, the gap junction protein Connexin 43 (Cx43) is essential for the formation of heart structures like the conotruncus.
What protein makes up gap junctions?
Gap junction (GJ) channels are paired hexameric structures composed of connexin (Cx) proteins1. More than twenty Cx isoforms are expressed in specific patterns in most cell populations throughout the body.
What size molecules can pass through gap junctions?
Gap junctions have traditionally been characterized as nonspecific pores between cells passing molecules up to 1 kDa in molecular mass.
What is a connexin and connexon and a gap junction?
In biology, a connexon, also known as a connexin hemichannel, is an assembly of six proteins called connexins that form the pore for a gap junction between the cytoplasm of two adjacent cells. This channel allows for bidirectional flow of ions and signaling molecules.
Do all cells have gap junctions?
Gap junctions are aggregates of intercellular channels that permit direct cell–cell transfer of ions and small molecules. Initially described as low-resistance ion pathways joining excitable cells (nerve and muscle), gap junctions are found joining virtually all cells in solid tissues.
What are Hemichannels?
Hemichannels, which are one half of the gap junction channels, have independent physiological roles. Although hemichannels consisting of connexins are more widely documented, hemichannels of pannexins, proteins homologous to invertebrate gap junction proteins also have been studied.
What is an example of gap junction?
These junctions allow communication between adjacent cells via the passage of small molecules directly from the cytoplasm of one cell to that of another. For example, heart muscle cells generate electrical current by the movement of inorganic salts. …
What is the main function of gap junction?
Gap junctions allow the exchange of ions, second messengers, and small metabolites between adjacent cells and are formed by two unrelated protein families, the pannexins and connexins. Mutations in connexin genes cause a variety of genetic disorders, implicating a critical role in tissue homeostasis.
What is the structure of connexin-43 protein?
Structure. Connexin-43 is a 43.0 kDa protein composed of 382 amino acids. GJA1 contains a long C-terminal tail, an N-terminal domain, and multiple transmembrane domains. The protein passes through the phospholipid bilayer four times, leaving its C- and N-terminals exposed to the cytoplasm.
Where is the GJA1 gene located on chromosome 6?
Gap junction alpha-1 protein (GJA1), also known as connexin 43 (Cx43), is a protein that in humans is encoded by the GJA1 gene on chromosome 6. As a connexin, GJA1 is a component of gap junctions, which allow for gap junction intercellular communication (GJIC) between cells to regulate cell death, proliferation,…
Which is the most ubiquitous member of the connexin family?
As a member of the connexin family, GJA1 is a component of gap junctions, which are intercellular channels that connect adjacent cells to permit the exchange of low molecular weight molecules, such as small ions and secondary messengers, to maintain homeostasis. GJA1 is the most ubiquitously expressed connexin and is detected in most cell types.
Where are the disulfide bonds found in GJA1?
Moreover, two extracellular loops form disulfide bonds that interact with two hexamers to form a complete gap junction channel. The connexin-43 internal ribosome entry site is an RNA element present in the 5′ UTR of the mRNA of GJA1.
What is gap junction protein connexin 43? Gap junctions are transmembrane complexes of connexin proteins that allow intercellular communication and the transfer of ions and small signaling molecules between adjacent cells1. In mice, the gap junction protein Connexin 43 (Cx43) is essential for the formation of heart structures like the conotruncus. What protein makes up…