| Innexin | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | Innexin | ||||||||
| Pfam | PF00876 | ||||||||
| InterPro | IPR000990 | ||||||||
| TCDB | 1.A.25 | ||||||||
| OPM superfamily | 194 | ||||||||
| OPM protein | 5h1r | ||||||||
| |||||||||
Innexins are transmembrane proteins that form gap junctions in invertebrates. Gap junctions are composed of membrane proteins that form a channel permeable to ions and small molecules connecting the cytoplasm of adjacent cells. Although gap junctions provide similar functions in all multicellular organisms, it was not known what proteins invertebrates used for this purpose until the late 1990s. While the connexin family of gap junction proteins was well-characterized in vertebrates, no homologues were found in non-chordates.
Innexins or related proteins are widespread among Eumetazoa, with the exception of echinoderms.[1]