Sequence-specific antibodies to connexins block intercellular calcium signaling through gap junctions

Cell Calcium. 1998 Jan;23(1):1-9. doi: 10.1016/s0143-4160(98)90069-0.

Abstract

Mechanical stimulation of a single cell in primary airway epithelial cell cultures induces an intercellular Ca2+ wave that has been proposed to be mediated via gap junctions. To investigate directly the role of gap junctions in this multicellular response, the effects of intracellularly-loaded sequence-specific connexin (gap junction) antibodies on the propagation of intercellular Ca2+ waves were evaluated. Electroporation of antibodies to the cytosolic loop (Des 1, generated to amino acids 102-112 + 116-124; and Des 5, amino acids 108-119), or to the carboxyl tail (Gap 9, amino acids 264-283) of connexin 32 inhibited the propagation of intercellular Ca2+ waves. The inhibitory effect of Des 1 antibody was competitively reversed by the co-loading of a peptide derived from a similar cytosolic loop sequence (Des 5 peptide). Conversely, the inhibitory effects on intercellular Ca2+ wave propagation of Gap 9 antibody was not altered by co-loading with the Des 5 peptide. Antibodies raised to peptide sequences within the extracellular loop (Gap 11, amino acids 151-187), or the cytoplasmically located amino terminus (Gap 10, amino acids 1-21) of connexin 32 did not inhibit mechanically-induced intercellular communication. Also ineffective in perturbing intercellular communication were antibodies raised to peptide sequences of the cytosolic loops of connexin 43 (Gap 15, amino acids 131-142) or connexin 26 (Des 3, amino acids 106-119). These data suggest that mechanically-induced Ca2+ waves in airway cell cultures are propagated through gap junctions made up of connexin 32 proteins.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibodies / pharmacology
  • Antibody Specificity
  • Binding Sites / physiology
  • Calcium / physiology*
  • Connexins / chemistry
  • Connexins / immunology*
  • Epithelial Cells / chemistry
  • Epithelial Cells / physiology
  • Gap Junction beta-1 Protein
  • Gap Junctions / physiology*
  • Lung / cytology
  • Microscopy, Confocal
  • Molecular Sequence Data
  • Peptide Fragments / immunology
  • Protein Structure, Tertiary
  • Rabbits
  • Signal Transduction / physiology*

Substances

  • Antibodies
  • Connexins
  • Peptide Fragments
  • Calcium