Editing Gap junction (section)

==Levels of organization==
In vertebrates, two pairs of six connexin proteins form a connexon. In invertebrates, six innexin proteins form an innexon. Otherwise, the structures are similar.
# The connexin genes (DNA) are transcribed to RNA, which is then translated to produce a connexin.
# One connexin protein has four [[transmembrane domain]]s<ref name="maeda" /><ref>{{cite journal |last1=Oshima |first1=A |last2=Tani |first2=K |last3=Fujiyoshi |first3=Y |title=Atomic structure of the innexin-6 gap junction channel determined by cryo-EM. |journal=Nat. Commun. |date=1 Dec 2016 |volume=7 |page=13681 |doi=10.1038/ncomms13681 |pmid=27905396|pmc=5146279 |bibcode=2016NatCo...713681O }}</ref>
# Six connexin proteins create one connexon channel a [[hemichannel]]. When identical connexin proteins join to form one connexon, it is called a homomeric connexon. When different connexin proteins join to form one connexon, it is called a heteromeric connexon.
# Two connexons, joined across a cell membrane, comprise a gap junction channel.<br />When two identical connexons come together to form a gap junction channel, it is called a homotypic channel. When one homomeric connexon and one heteromeric connexon come together, it is called a heterotypic gap junction channel. When two heteromeric connexons join, it is also called a heterotypic gap junction channel.
# Tens to thousands of gap junction channels cluster in areas to enable connexon pairs to form.<ref name=clusters>{{cite journal |last1=Lauf |first1=Undine |last2=Giepmans |first2=Ben N. G. |last3=Lopez |first3=Patricia |last4=Braconnot |first4=Sébastien |last5=Chen |first5=Shu-Chih |last6=Falk |first6=Matthias M. |title=Dynamic trafficking and delivery of connexons to the plasma membrane and accretion to gap junctions in living cells |journal=Proceedings of the National Academy of Sciences |date=6 August 2002 |volume=99 |issue=16 |pages=10446–10451 |doi=10.1073/pnas.162055899|pmid=12149451 |pmc=124935 |doi-access=free |bibcode=2002PNAS...9910446L }}</ref> The macromolecular complex is called a gap junction plaque. Molecules other than connexins are involved in gap junction plaques including [[tight junction protein 1]] and [[sodium channel]]s.<ref name="Connexin 43 gap junction plaque end"/><ref name="Localization of Na + channel cluste">{{cite journal |last1=Ivanovic |first1=Ena |last2=Kucera |first2=Jan P. |title=Localization of Na + channel clusters in narrowed perinexi of gap junctions enhances cardiac impulse transmission via ephaptic coupling: a model study |journal=The Journal of Physiology |date=November 2021 |volume=599 |issue=21 |pages=4779–4811 |doi=10.1113/JP282105|doi-access=free |pmid=34533834 |pmc=9293295 }}</ref>