Molecular cloning and functional expression of the mouse gap junction gene connexin-57 in human HeLa cells

J Biol Chem. 1999 May 21;274(21):14716-23. doi: 10.1074/jbc.274.21.14716.


A new mouse connexin gene has been isolated that codes for a connexin protein of 505 amino acid residues. Based on the predicted molecular mass of 57.115 kDa, it has been designated connexin-57. Similar to most other mouse connexin genes, the coding region of connexin-57 is not interrupted by introns and exists in the mouse genome as a single-copy gene. Within the connexin family, this new gene shows highest sequence identity to porcine connexin-60 in the alpha group of connexins. The connexin-57 gene was mapped to a position on mouse chromosome 4, 30 centimorgans proximal to a cluster of previously mapped connexin genes. Low levels of connexin-57 mRNA were detected in skin, heart, kidney, testis, ovary, intestine, and in the mouse embryo after 8 days post coitum, but expression was not detected in brain, sciatic nerve or liver. In order to analyze gene function, the connexin-57 coding region was expressed by transfection in human HeLa cells, where it restored homotypic intercellular transfer of microinjected neurobiotin. Heterotypic transfer was observed between HeLa connexin-57 transfectants and HeLa cells, expressing murine connexin-43, -37, or -30.3. Double whole-cell voltage clamp analyses revealed that HeLa-connexin-57 transfectants expressed about 10 times more channels than parental HeLa cells. Voltage gating by transjunctional and transmembrane voltages as well as unitary conductance ( approximately 27 picosiemens) were different from intrinsic connexin channels in parental HeLa cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Chromosome Mapping
  • Cloning, Molecular
  • Connexins / biosynthesis
  • Connexins / genetics*
  • Gap Junctions / genetics*
  • Gap Junctions / physiology
  • HeLa Cells
  • Humans
  • Mice
  • Molecular Sequence Data
  • RNA, Messenger / biosynthesis


  • Connexins
  • Gja10 protein, mouse
  • RNA, Messenger

Associated data

  • GENBANK/AJ010741