Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
J Neurosci
2004 Jan 28;244:886-94. doi: 10.1523/JNEUROSCI.3676-03.2004.
Show Gene links
Show Anatomy links
Molecular basis of gap junctional communication in the CNS of the leech Hirudo medicinalis.
Dykes IM
,
Freeman FM
,
Bacon JP
,
Davies JA
.
???displayArticle.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.
Aguinaldo,
Evidence for a clade of nematodes, arthropods and other moulting animals.
1997, Pubmed
Aguinaldo,
Evidence for a clade of nematodes, arthropods and other moulting animals.
1997,
Pubmed
Alvarez-Maubecin,
Functional coupling between neurons and glia.
2000,
Pubmed
Baker,
RNAi of the receptor tyrosine phosphatase HmLAR2 in a single cell of an intact leech embryo leads to growth-cone collapse.
2000,
Pubmed
Barrio,
Gap junctions formed by connexins 26 and 32 alone and in combination are differently affected by applied voltage.
1991,
Pubmed
,
Xenbase
Baylor,
Chemical and electrical synaptic connexions between cutaneous mechanoreceptor neurones in the central nervous system of the leech.
1969,
Pubmed
Carbonetto,
A regenerating neurone in the leech can form an electrical synapse on its severed axon segment.
1977,
Pubmed
Coggeshall,
Gap junctions between identified glial cells in the leech.
1974,
Pubmed
Cserzö,
Prediction of transmembrane alpha-helices in prokaryotic membrane proteins: the dense alignment surface method.
1997,
Pubmed
Davis,
Voltage-dependent properties of electrical synapses formed between identified leech neurones in vitro.
1989,
Pubmed
De-Miguel,
Spread of synaptic potentials through electrical synapses in Retzius neurones of the leech.
2001,
Pubmed
Deitmer,
Leech giant glial cell: functional role in a simple nervous system.
1999,
Pubmed
Fernández-de-Miguel,
Synapse formation and function: insights from identified leech neurons in culture.
1995,
Pubmed
Giaume,
Voltage-clamp analysis of a crayfish rectifying synapse.
1987,
Pubmed
Harris,
Emerging issues of connexin channels: biophysics fills the gap.
2001,
Pubmed
Heitler,
Different types of rectification at electrical synapses made by a single crayfish neurone investigated experimentally and by computer simulation.
1991,
Pubmed
Jaslove,
The mechanism of rectification at the electrotonic motor giant synapse of the crayfish.
,
Pubmed
KUFFLER,
GLIA IN THE LEECH CENTRAL NERVOUS SYSTEM: PHYSIOLOGICAL PROPERTIES AND NEURON-GLIA RELATIONSHIP.
1964,
Pubmed
Kelmanson,
Altering electrical connections in the nervous system of the pteropod mollusc Clione limacina by neuronal injections of gap junction mRNA.
2002,
Pubmed
Kumar,
The gap junction communication channel.
1996,
Pubmed
Landesman,
Innexin-3 forms connexin-like intercellular channels.
1999,
Pubmed
,
Xenbase
Larsen,
Structural diversity of gap junctions. A review.
1977,
Pubmed
Marder,
Roles for electrical coupling in neural circuits as revealed by selective neuronal deletions.
1984,
Pubmed
Muller,
Synapses between neurones in the central nervous system of the leech.
1979,
Pubmed
Page,
TreeView: an application to display phylogenetic trees on personal computers.
1996,
Pubmed
Panchin,
A ubiquitous family of putative gap junction molecules.
2000,
Pubmed
Phelan,
Innexins get into the gap.
2001,
Pubmed
Phelan,
Innexins: a family of invertebrate gap-junction proteins.
1998,
Pubmed
Phelan,
Drosophila Shaking-B protein forms gap junctions in paired Xenopus oocytes.
1998,
Pubmed
,
Xenbase
Potenza,
Cloning and molecular characterization of the first innexin of the phylum annelida-expression of the gene during development.
2002,
Pubmed
Pumplin,
Distinctions between gap junctions and sites of intermediate filament attachment in the leech C.N.S.
1983,
Pubmed
Rela,
Coactivation of motoneurons regulated by a network combining electrical and chemical synapses.
2003,
Pubmed
Shen,
Ultrastructure of electrical synapses between nociceptive and anterior pagoda neurons in the CNS of the leech (Whitmania pigra).
2002,
Pubmed
Spray,
Equilibrium properties of a voltage-dependent junctional conductance.
1981,
Pubmed
,
Xenbase
Starich,
Innexins in C. elegans.
2001,
Pubmed
Stebbings,
Two Drosophila innexins are expressed in overlapping domains and cooperate to form gap-junction channels.
2000,
Pubmed
,
Xenbase
Stebbings,
Gap junctions in Drosophila: developmental expression of the entire innexin gene family.
2002,
Pubmed
Swenson,
Formation of gap junctions by expression of connexins in Xenopus oocyte pairs.
1989,
Pubmed
,
Xenbase
Taghert,
Guidance of pioneer growth cones: filopodial contacts and coupling revealed with an antibody to Lucifer Yellow.
1982,
Pubmed
Thompson,
CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice.
1994,
Pubmed
Wolszon,
Growth cone "collapse" in vivo: are inhibitory interactions mediated by gap junctions?
1994,
Pubmed
