Innexins form two types of channels.
Injury to the central nervous system triggers glial calcium waves in both vertebrates and invertebrates. In vertebrates the pannexin1 ATP-release channel appears to provide for calcium wave initiation and propagation. The innexins, which form invertebrate gap junctions and have sequence similarity with the pannexins, are candidates to form non-junctional membrane channels. Two leech innexins previously demonstrated in glia were expressed in frog oocytes. In addition to making gap junctions, innexins also formed non-junctional membrane channels with properties similar to those of pannexons. In addition, carbenoxolone reversibly blocked the loss of carboxyfluorescein dye into the bath from the giant glial cells in the connectives of the leech nerve cord, which are known to express the innexins we assayed.
Department of Physiology and Biophysics, University of Miami, School of Medicine, Miami, FL 33136, USA.
Li
L
Bao
Stuart
S
Samuels
Silviu
S
Locovei
Eduardo R
ER
Macagno
Kenneth J
KJ
Muller
Gerhard
G
Dahl
D000818:Animals; D020013:Calcium Signaling; D017630:Connexins / Q000502:physiology*; D003593:Cytoplasm / Q000378:metabolism; D017629:Gap Junctions / Q000378:metabolism; D007865:Leeches / Q000378:metabolism; D008954:Models, Biological; D009457:Neuroglia / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism; D018408:Patch-Clamp Techniques; D014981:Xenopus / Q000378:metabolism
D017630:Connexins