Functional properties of mouse connexin30.2 expressed in the conduction system of the heart

Maria M. Kreuzberg, Goran Söhl, Jung Sun Kim, Vytautas Verselis, Klaus Willecke, Feliksas F. Bukauskas

Research output: Contribution to journalArticle

99 Citations (Scopus)

Abstract

Gap junction channels composed of connexin (Cx) 40, Cx43, and Cx45 proteins are known to be necessary for impulse propagation through the heart. Here, we report mouse connexin30.2 (mCx30.2) to be a new cardiac connexin that is expressed mainly in the conduction system of the heart. Antibodies raised to the cytoplasmic loop or the C-terminal regions of mCx30.2 recognized this protein in mouse heart as well as in HeLa cells transfected with wild-type mCx30.2 or mCx30.2 fused with enhanced green fluorescent protein (mCx30.2-EGFP). Immunofluorescence analyses of adult hearts yielded positive signals within the sinoatrial node, atrioventricular node, and A-V bundle of the cardiac conduction system. Dye transfer studies demonstrated that mCx30.2 and mCx30.2-EGFP channels discriminate poorly on the basis of charge, but do not allow permeation of tracers >400 Da. Both mCx30.2 and mCx30.2-EGFP gap junctional channels exhibited weak sensitivity to transjunctional voltage (Vj) and a single channel conductance of ≈9 pS, which is the lowest among all members of the connexin family measured in HeLa cell transfectants. HeLa mCx30.2-EGFP transfectants when paired with cells expressing Cx40, Cx43, or Cx45 formed functional heterotypic gap junction channels that exhibited low unitary conductances (15 to 18 pS), rectifying open channel I-V relations and asymmetric Vj dependence. The electrical properties of homo- and hetero-typic junctions involving mCx30.2 may contribute to slow propagation velocity in nodal tissues and directional asymmetry of excitation spread in the AV nodal region.

Original languageEnglish (US)
Pages (from-to)1169-1177
Number of pages9
JournalCirculation Research
Volume96
Issue number11
DOIs
StatePublished - Jun 10 2005

Fingerprint

Heart Conduction System
Connexin 43
Connexins
Gap Junctions
HeLa Cells
Atrioventricular Node
Sinoatrial Node
Fluorescent Antibody Technique
Coloring Agents

Keywords

  • Atrioventricular node
  • Connexin
  • Gap junctions
  • MCx30.2
  • Sinoatrial node

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine

Cite this

Functional properties of mouse connexin30.2 expressed in the conduction system of the heart. / Kreuzberg, Maria M.; Söhl, Goran; Kim, Jung Sun; Verselis, Vytautas; Willecke, Klaus; Bukauskas, Feliksas F.

In: Circulation Research, Vol. 96, No. 11, 10.06.2005, p. 1169-1177.

Research output: Contribution to journalArticle

Kreuzberg, Maria M. ; Söhl, Goran ; Kim, Jung Sun ; Verselis, Vytautas ; Willecke, Klaus ; Bukauskas, Feliksas F. / Functional properties of mouse connexin30.2 expressed in the conduction system of the heart. In: Circulation Research. 2005 ; Vol. 96, No. 11. pp. 1169-1177.
@article{c2743524625d4ef6988c4a4611c9ef2a,
title = "Functional properties of mouse connexin30.2 expressed in the conduction system of the heart",
abstract = "Gap junction channels composed of connexin (Cx) 40, Cx43, and Cx45 proteins are known to be necessary for impulse propagation through the heart. Here, we report mouse connexin30.2 (mCx30.2) to be a new cardiac connexin that is expressed mainly in the conduction system of the heart. Antibodies raised to the cytoplasmic loop or the C-terminal regions of mCx30.2 recognized this protein in mouse heart as well as in HeLa cells transfected with wild-type mCx30.2 or mCx30.2 fused with enhanced green fluorescent protein (mCx30.2-EGFP). Immunofluorescence analyses of adult hearts yielded positive signals within the sinoatrial node, atrioventricular node, and A-V bundle of the cardiac conduction system. Dye transfer studies demonstrated that mCx30.2 and mCx30.2-EGFP channels discriminate poorly on the basis of charge, but do not allow permeation of tracers >400 Da. Both mCx30.2 and mCx30.2-EGFP gap junctional channels exhibited weak sensitivity to transjunctional voltage (Vj) and a single channel conductance of ≈9 pS, which is the lowest among all members of the connexin family measured in HeLa cell transfectants. HeLa mCx30.2-EGFP transfectants when paired with cells expressing Cx40, Cx43, or Cx45 formed functional heterotypic gap junction channels that exhibited low unitary conductances (15 to 18 pS), rectifying open channel I-V relations and asymmetric Vj dependence. The electrical properties of homo- and hetero-typic junctions involving mCx30.2 may contribute to slow propagation velocity in nodal tissues and directional asymmetry of excitation spread in the AV nodal region.",
keywords = "Atrioventricular node, Connexin, Gap junctions, MCx30.2, Sinoatrial node",
author = "Kreuzberg, {Maria M.} and Goran S{\"o}hl and Kim, {Jung Sun} and Vytautas Verselis and Klaus Willecke and Bukauskas, {Feliksas F.}",
year = "2005",
month = "6",
day = "10",
doi = "10.1161/01.RES.0000169271.33675.05",
language = "English (US)",
volume = "96",
pages = "1169--1177",
journal = "Circulation Research",
issn = "0009-7330",
publisher = "Lippincott Williams and Wilkins",
number = "11",

}

TY - JOUR

T1 - Functional properties of mouse connexin30.2 expressed in the conduction system of the heart

AU - Kreuzberg, Maria M.

AU - Söhl, Goran

AU - Kim, Jung Sun

AU - Verselis, Vytautas

AU - Willecke, Klaus

AU - Bukauskas, Feliksas F.

PY - 2005/6/10

Y1 - 2005/6/10

N2 - Gap junction channels composed of connexin (Cx) 40, Cx43, and Cx45 proteins are known to be necessary for impulse propagation through the heart. Here, we report mouse connexin30.2 (mCx30.2) to be a new cardiac connexin that is expressed mainly in the conduction system of the heart. Antibodies raised to the cytoplasmic loop or the C-terminal regions of mCx30.2 recognized this protein in mouse heart as well as in HeLa cells transfected with wild-type mCx30.2 or mCx30.2 fused with enhanced green fluorescent protein (mCx30.2-EGFP). Immunofluorescence analyses of adult hearts yielded positive signals within the sinoatrial node, atrioventricular node, and A-V bundle of the cardiac conduction system. Dye transfer studies demonstrated that mCx30.2 and mCx30.2-EGFP channels discriminate poorly on the basis of charge, but do not allow permeation of tracers >400 Da. Both mCx30.2 and mCx30.2-EGFP gap junctional channels exhibited weak sensitivity to transjunctional voltage (Vj) and a single channel conductance of ≈9 pS, which is the lowest among all members of the connexin family measured in HeLa cell transfectants. HeLa mCx30.2-EGFP transfectants when paired with cells expressing Cx40, Cx43, or Cx45 formed functional heterotypic gap junction channels that exhibited low unitary conductances (15 to 18 pS), rectifying open channel I-V relations and asymmetric Vj dependence. The electrical properties of homo- and hetero-typic junctions involving mCx30.2 may contribute to slow propagation velocity in nodal tissues and directional asymmetry of excitation spread in the AV nodal region.

AB - Gap junction channels composed of connexin (Cx) 40, Cx43, and Cx45 proteins are known to be necessary for impulse propagation through the heart. Here, we report mouse connexin30.2 (mCx30.2) to be a new cardiac connexin that is expressed mainly in the conduction system of the heart. Antibodies raised to the cytoplasmic loop or the C-terminal regions of mCx30.2 recognized this protein in mouse heart as well as in HeLa cells transfected with wild-type mCx30.2 or mCx30.2 fused with enhanced green fluorescent protein (mCx30.2-EGFP). Immunofluorescence analyses of adult hearts yielded positive signals within the sinoatrial node, atrioventricular node, and A-V bundle of the cardiac conduction system. Dye transfer studies demonstrated that mCx30.2 and mCx30.2-EGFP channels discriminate poorly on the basis of charge, but do not allow permeation of tracers >400 Da. Both mCx30.2 and mCx30.2-EGFP gap junctional channels exhibited weak sensitivity to transjunctional voltage (Vj) and a single channel conductance of ≈9 pS, which is the lowest among all members of the connexin family measured in HeLa cell transfectants. HeLa mCx30.2-EGFP transfectants when paired with cells expressing Cx40, Cx43, or Cx45 formed functional heterotypic gap junction channels that exhibited low unitary conductances (15 to 18 pS), rectifying open channel I-V relations and asymmetric Vj dependence. The electrical properties of homo- and hetero-typic junctions involving mCx30.2 may contribute to slow propagation velocity in nodal tissues and directional asymmetry of excitation spread in the AV nodal region.

KW - Atrioventricular node

KW - Connexin

KW - Gap junctions

KW - MCx30.2

KW - Sinoatrial node

UR - http://www.scopus.com/inward/record.url?scp=20444465223&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=20444465223&partnerID=8YFLogxK

U2 - 10.1161/01.RES.0000169271.33675.05

DO - 10.1161/01.RES.0000169271.33675.05

M3 - Article

C2 - 15879306

AN - SCOPUS:20444465223

VL - 96

SP - 1169

EP - 1177

JO - Circulation Research

JF - Circulation Research

SN - 0009-7330

IS - 11

ER -