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.
Connexin46, a novel lens gap junction protein, induces voltage-gated currents in nonjunctional plasma membrane of Xenopus oocytes.
Paul DL, Ebihara L, Takemoto LJ, Swenson KI, Goodenough DA.
???displayArticle.abstract???
Gap junctions are composed of a family of structural proteins called connexins, which oligomerize into intercellular channels and function to exchange low molecular weight metabolites and ions between adjacent cells. We have cloned a new member of the connexin family from lens cDNA, with a predicted molecular mass of 46 kD, called rat connexin46 (Cx46). Since a full-length cDNA corresponding to the 2.8-kb mRNA was not obtained, the stop codon and surrounding sequences were confirmed from rat genomic DNA. The RNA coding for this protein is abundant in lens fibers and detectable in both myocardium and kidney. Western analysis of both rat and bovine lens membrane proteins, using the anti-MP70 monoclonal antibody 6-4-B2-C6 and three anti-peptide antibodies against Cx46 demonstrates that Cx46 and MP70 are different proteins. Immunocytochemistry demonstrates that both proteins are localized in the same lens fiber junctional maculae. Synthesis of Cx46 in either reticulocyte lysate or Xenopus oocytes yields a 46-kD polypeptide; all anti-Cx46 antisera recognize a protein in rat lens membranes 5-10 kD larger, suggesting substantive lenticular posttranslational processing of the native translation product. Oocytes that have synthesized Cx46 depolarize and lyse within 24 h, a phenomenon never observed after expression of rat connexins 32 or 43 (Cx32 and Cx43). Lysis is prevented by osmotically buffering the oocytes with 5% Ficoll. Ficoll-buffered oocytes expressing Cx46 are permeable to Lucifer Yellow but not FITC-labeled BSA, indicating the presence of selective membrane permeabilities. Cx43-expressing oocytes are impermeable to Lucifer Yellow. Voltage-gated whole cell currents are measured in oocytes injected with dilute concentrations of Cx46 but not Cx43 mRNA. These currents are activated at potentials positive to -10 mV. Unlike other connexins expressed in Xenopus oocytes, these results suggest that unprocessed Cx46 induces nonselective channels in the oolemma that are voltage dependent and opened by large depolarizations.
Bennett,
Gap junctions, electrotonic coupling, and intercellular communication.
1978, Pubmed,
Xenbase
Bennett,
Gap junctions, electrotonic coupling, and intercellular communication.
1978,
Pubmed
,
Xenbase Beyer,
Connexin family of gap junction proteins.
1990,
Pubmed Beyer,
Evidence that the gap junction protein connexin-43 is the ATP-induced pore of mouse macrophages.
1991,
Pubmed Beyer,
Connexin43: a protein from rat heart homologous to a gap junction protein from liver.
1987,
Pubmed Beyer,
Antisera directed against connexin43 peptides react with a 43-kD protein localized to gap junctions in myocardium and other tissues.
1989,
Pubmed Brink,
Patch clamp recordings from membranes which contain gap junction channels.
1989,
Pubmed Burt,
Single-channel events and gating behavior of the cardiac gap junction channel.
1988,
Pubmed COHEN,
THE ELECTRON MICROSCOPY OF THE NORMAL HUMAN LENS.
1965,
Pubmed Crow,
Phosphorylation of connexin43 gap junction protein in uninfected and Rous sarcoma virus-transformed mammalian fibroblasts.
1990,
Pubmed Dahl,
Expression of functional cell-cell channels from cloned rat liver gap junction complementary DNA.
1987,
Pubmed
,
Xenbase Duncan,
The site of the ion restricting membranes in the toad lens.
1969,
Pubmed Ebihara,
Cloning and expression of a Xenopus embryonic gap junction protein.
1989,
Pubmed
,
Xenbase Eisenberg,
Current-voltage relationships in the crystalline lens.
1976,
Pubmed Feinberg,
A technique for radiolabeling DNA restriction endonuclease fragments to high specific activity.
1983,
Pubmed Fishman,
Molecular characterization and functional expression of the human cardiac gap junction channel.
1990,
Pubmed Goodenough,
Lens metabolic cooperation: a study of mouse lens transport and permeability visualized with freeze-substitution autoradiography and electron microscopy.
1980,
Pubmed Goodenough,
Topological distribution of two connexin32 antigenic sites in intact and split rodent hepatocyte gap junctions.
1988,
Pubmed Goodenough,
Lens gap junctions: a structural hypothesis for nonregulated low-resistance intercellular pathways.
1979,
Pubmed Gruijters,
Immunolocalization of MP70 in lens fiber 16-17-nm intercellular junctions.
1987,
Pubmed Helms,
A new method for purifying lambda DNA from phage lysates.
1985,
Pubmed Hertzberg,
A protein homologous to the 27,000 dalton liver gap junction protein is present in a wide variety of species and tissues.
1984,
Pubmed Kistler,
Structural and molecular biology of the eye lens membranes.
1989,
Pubmed Kistler,
Homologies between gap junction proteins in lens, heart and liver.
1988,
Pubmed Kistler,
Identification of a 70,000-D protein in lens membrane junctional domains.
1985,
Pubmed Krieg,
Functional messenger RNAs are produced by SP6 in vitro transcription of cloned cDNAs.
1984,
Pubmed
,
Xenbase Laird,
Turnover and phosphorylation dynamics of connexin43 gap junction protein in cultured cardiac myocytes.
1991,
Pubmed Leeson,
Lens of the rat eye: an electron microscope and freeze-etch study.
1971,
Pubmed Mathias,
The lens as a nonuniform spherical syncytium.
1981,
Pubmed Methfessel,
Patch clamp measurements on Xenopus laevis oocytes: currents through endogenous channels and implanted acetylcholine receptor and sodium channels.
1986,
Pubmed
,
Xenbase Miller,
Gap junction structures after experimental alteration of junctional channel conductance.
1985,
Pubmed Miller,
Evidence for two physiologically distinct gap junctions expressed by the chick lens epithelial cell.
1986,
Pubmed Musil,
Differential phosphorylation of the gap junction protein connexin43 in junctional communication-competent and -deficient cell lines.
1990,
Pubmed Neyton,
Single-channel currents of an intercellular junction.
,
Pubmed Nicholson,
Two homologous protein components of hepatic gap junctions.
,
Pubmed Paul,
Preparation, characterization, and localization of antisera against bovine MP26, an integral protein from lens fiber plasma membrane.
1983,
Pubmed Paul,
Molecular cloning of cDNA for rat liver gap junction protein.
1986,
Pubmed Philipson,
Cell contacts in human and bovine lenses.
1975,
Pubmed Rae,
The movement of procion dye in the crystalline lens.
1974,
Pubmed Rae,
Lanthanum and procion yellow as extracellular markers in the crystalline lens of the rat.
1979,
Pubmed Rae,
The electrophysiology of the crystalline lens.
1979,
Pubmed Schuetze,
Dye transfer between cells of the embryonic chick lens becomes less sensitive to CO2 treatment with development.
1982,
Pubmed Somogyi,
Cell-to-cell channel conductance during loss of gap junctional coupling in pairs of pancreatic acinar and Chinese hamster ovary cells.
1988,
Pubmed Swenson,
Formation of gap junctions by expression of connexins in Xenopus oocyte pairs.
1989,
Pubmed
,
Xenbase Swenson,
Tyrosine phosphorylation of the gap junction protein connexin43 is required for the pp60v-src-induced inhibition of communication.
1990,
Pubmed
,
Xenbase Takemoto,
Antisera to synthetic peptides of lens MIP26K (major intrinsic polypeptide): characterization and use as site-specific probes of membrane changes in the aging human lens.
1985,
Pubmed Traub,
Comparative characterization of the 21-kD and 26-kD gap junction proteins in murine liver and cultured hepatocytes.
1989,
Pubmed Veenstra,
Cardiac gap junction channel activity in embryonic chick ventricle cells.
1988,
Pubmed Werner,
Formation of hybrid cell-cell channels.
1989,
Pubmed
,
Xenbase Wilson,
Optimization of asymmetric polymerase chain reaction for rapid fluorescent DNA sequencing.
1990,
Pubmed Young,
Functional assembly of gap junction conductance in lipid bilayers: demonstration that the major 27 kd protein forms the junctional channel.
1987,
Pubmed Zampighi,
The structural organization and protein composition of lens fiber junctions.
1989,
Pubmed
