Pathway maps

Cell adhesion_Gap junctions
Cell adhesion_Gap junctions

Object List (links open in MetaCore):

Connexin 32, Connexin 50, <cytosol> Na('+) = <extracellular region> Na('+), Occludin, ZO-1, <extracellular region> K('+) = <cytosol> K('+), <cytosol> K('+) = <extracellular region> K('+), Connexin 45, Connexin 40, Tubulin heterodimers (in microtubules), Connexin 46, Tubulin alpha, Tubulin beta, Connexin 43, Connexin 37, Connexin 26, Connexin 46, Actin, ZO-3, Cingulin, ZO-2, K(+) cytosol, Connexin 50, c-Src, Connexin 37, Connexin 43, Connexin 45, K(+) , Na(+), Connexin 40, PKC, <extracellular region> Na('+) = <cytosol> Na('+), Connexin 32, Caveolin-1, Connexin 31, Connexin 36, Na(+) cytosol


Gap junctions

Gap junction channels are intercellular channels that allow passage of ions, such as K(+) and Na(+), and other small molecules between neighboring cells. These channels are formed from two multimeric subunits called hemichannels, or connexons, that reside in plasma membranes of two closely opposed cells.

Connexons are composed of six transmembrane protein subunits called Connexins [1]. The double membrane channel, or gap junction, is generated directly and couples the cytoplasms of the interacting cells. This leads to integration and co-ordination of the cellular metabolism, signaling and function, e.g.,secretion or contraction in cell assemblies [2].

Interactions of Connexins with Zona occludens proteins ( ZO-1, ZO-2 and ZO-3 ) couple gap junction channels with the tight junction components, such as Occludin, and with cytoskeletal elements, such as Actin filaments [3].

Connexins 43 and 36 can anchor Microtubules (consisting of the Alpha/Beta-tubulin dimers) to gap junctions and thereby can affect the properties of microtubules in contacted cells [4], [5].


  1. Ebihara L
    New roles for connexons. News in physiological sciences : an international journal of physiology produced jointly by the International Union of Physiological Sciences and the American Physiological Society. 2003 Jun;18:100-3
  2. Evans WH, De Vuyst E, Leybaert L
    The gap junction cellular internet: connexin hemichannels enter the signalling limelight. The Biochemical journal 2006 Jul 1;397(1):1-14
  3. Nielsen PA, Baruch A, Shestopalov VI, Giepmans BN, Dunia I, Benedetti EL, Kumar NM
    Lens connexins alpha3Cx46 and alpha8Cx50 interact with zonula occludens protein-1 (ZO-1). Molecular biology of the cell 2003 Jun;14(6):2470-81
  4. Giepmans BN, Verlaan I, Hengeveld T, Janssen H, Calafat J, Falk MM, Moolenaar WH
    Gap junction protein connexin-43 interacts directly with microtubules. Current biology : CB 2001 Sep 4;11(17):1364-8
  5. Sitaramayya A, Crabb JW, Matesic DF, Margulis A, Singh V, Pulukuri S, Dang L
    Connexin 36 in bovine retina: lack of phosphorylation but evidence for association with phosphorylated proteins. Visual neuroscience 2003 Jul-Aug;20(4):385-95