Connexin 43 and Permeability through Gap Junctions

Mon, 03/11/2013 - 11:35

Gap junctions consist of Connexins (Cx), a family of proteins that form channels linking the cytoplasm of adjacent cells. All Connexin molecules have four membrane-spanning domains, two extracellular domains, and a cytoplasmic carboxy-terminal tail of varying length that has an important role in the regulation of the gating properties of the channel. Interestingly Connexin 43 also known as gap junction alpha-1 protein is one of the most abundant gap-junction protein. Several studies have documented using immunoblotting of cell lysates that at least three Connexin 43-specific bands. While bands P1 and P2 are phosphorylated on multiple, unidentified serine residues in gap-junction plaques using anti-Connexin 43 antibodies. Immunofloresecence studies using a monoclonal antibody against the 23 residues at the C-terminus of connexin 43 bound primarily to connexin 43 present in the Golgi apparatus, suggesting that the conformation of Ser364/Ser365 is important for intracellular localization (1).

IHC analysis of Connexin 43 in human brain tissue IHC analysis of Connexin 43 in human brain tissue

A sequence-specific monoclonal antibody directed against connexin 43 was also shown to be specific for the unphosphorylated form of this protein. In tissues and cultured cells containing different phosphorylated and unphosphorylated forms of Connexin 43, the antibody detected only the latter as shown by Immunoblots. Connexin 43 has also been suggested to play a critical role in the physiology of hearing by participating in the recycling of potassium to the cochlear endolymph. Additionally Connexin 43 is also a regulator of bladder functional capacity by enhancing intercellular electrical and chemical transmission, thus sensitizing bladder muscles to cholinergic neural stimuli and causing them to contract (2). Biochemical and electrophysiological evidence suggests that Connexin 43 and other Connexins extensively mix to form heteromeric channels; however, individual Connexin components dominate aspects of the physiological behavior of these channels. Novus Biologicals is in the forefront of your research needs and offers a wide variety of tools in the form of cell lysates, RNAi and antibodies against connexin 43.



  1. PMID: 17714073
  2. PMID: 22411987


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