Length of the two extracellular loops of connexins and innexins (invertebrate analogs of the connexins) family

Range in innexins ~50: in connexins ~30 amino acids
Organism Metazoa animals
Reference Simonsen KT, Moerman DG, Naus CC. Gap junctions in C. elegans. Front Physiol. 2014 Feb 11 5 :40 doi: 10.3389/fphys.2014.00040 p.1 left column top paragraphPubMed ID24575048
Primary Source Phelan P. Innexins: members of an evolutionarily conserved family of gap-junction proteins. Biochim Biophys Acta. 2005 Jun 10 1711(2):225-45 DOI: 10.1016/j.bbamem.2004.10.004 AND Oshima A, Matsuzawa T, Nishikawa K, Fujiyoshi Y. Oligomeric structure and functional characterization of Caenorhabditis elegans Innexin-6 gap junction protein. J Biol Chem. 2013 Apr 12 288(15):10513-21. doi: 10.1074/jbc.M112.428383PubMed ID15921654, 23460640
Method Primary source Oshima et al. abstract: "Innexin is the molecular component of invertebrate gap junctions. Here [investigators] successfully expressed and purified Caenorhabditis elegans innexin-6 (INX-6) gap junction channels and characterized the molecular dimensions and channel permeability using electron microscopy (EM) and microinjection of fluorescent dye tracers, respectively. Negative staining and thin-section EM of isolated INX-6 gap junction membranes revealed a loosely packed hexagonal lattice and a greater cross-sectional width than that of connexin26 and connexin43 (Cx43)-GFP. In gel filtration analysis, the elution profile of purified INX-6 channels in dodecyl maltoside solution exhibited a peak at ∼400 kDa that was shifted to ∼800 kDa in octyl glucose neopentyl glycol."
Comments P.1 left column top paragraph: "The two extracellular loops of innexins are thought to be longer than in the connexins, i.e., ∼50 amino acids for innexins and ∼30 amino acids for connexins (primary sources)." Primary source Oshima et al. abstract: "Based on these findings, INX-6 channels have a larger overall structure and greater permeability than connexin channels."
Entered by Uri M
ID 117153