Dykes, IM;
Freeman, FM;
Bacon, JP;
Davies, JA;
(2004)
Molecular basis of gap junctional communication in the CNS of the leech Hirudo medicinalis.
Journal of Neuroscience
, 24
(4)
886 - 894.
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Abstract
Gap junctions are intercellular channels that allow the passage of ions and small molecules between cells. In the nervous system, gap junctions mediate electrical coupling between neurons. Despite sharing a common topology and similar physiology, two unrelated gap junction protein families exist in the animal kingdom. Vertebrate gap junctions are formed by members of the connexin family, whereas invertebrate gap junctions are composed of innexin proteins. Here we report the cloning of two innexins from the leech Hirudo medicinalis. These innexins show a differential expression in the leech CNS: Hm-inx1 is expressed by every neuron in the CNS but not in glia, whereas Hm-inx2 is expressed in glia but not neurons. Heterologous expression in the paired Xenopus oocyte system demonstrated that both innexins are able to form functional homotypic gap junctions. Hm-inx1 forms channels that are not strongly gated. In contrast, Hm-inx2 forms channels that are highly voltage-dependent; these channels demonstrate properties resembling those of a double rectifier. In addition, Hm-inx1 and Hm-inx2 are able to cooperate to form heterotypic gap junctions in Xenopus oocytes. The behavior of these channels is primarily that predicted from the properties of the constituent hemichannels but also demonstrates evidence of an interaction between the two. This work represents the first demonstration of a functional gap junction protein from a Lophotrochozoan animal and supports the hypothesis that connexin-based communication is restricted to the deuterostome clade.
Type: | Article |
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Title: | Molecular basis of gap junctional communication in the CNS of the leech Hirudo medicinalis. |
Open access status: | An open access version is available from UCL Discovery |
Language: | English |
Additional information: | This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. The license allows you to copy, distribute, and transmit the work, as well as adapting it. However, you must attribute the work to the author (but not in any way that suggests that they endorse you or your use of the work), and cannot use the work for commercial purposes without prior permission of the author. If you alter or build upon this work, you can distribute the resulting work only under the same or similar license to this one. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/ or send a letter to Creative Commons, 444 Castro Street, Suite 900, Mountain View, California, 94041, USA. |
UCL classification: | UCL > Provost and Vice Provost Offices UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences |
URI: | https://discovery.ucl.ac.uk/id/eprint/1321080 |
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