Molecular and Cellular Biochemistry

, Volume 242, Issue 1–2, pp 35–38 | Cite as

The carboxy-tail of connexin-43 localizes to the nucleus and inhibits cell growth

  • Xitong Dang
  • Bradley W. Doble
  • Elissavet Kardami


Gap junctions are plasma membrane intercellular communication channels that in addition to ensuring electrical coupling and coordinated mechanical activity, can act as growth suppressors. To define the role of a non-channel forming domain of connexin-43 (Cx43), the main constituent of cardiomyocyte gap junctions, on growth regulation, we expressed its C-terminal portion (CT-Cx43) in cardiomyocytes and HeLa cells. In addition to broad cytoplasmic localization, CT-Cx43 was also localized to the nucleus of both cell types, detected by immunofluorescence as well as immunoblotting of subcellular fractions. Furthermore, stable expression of CT-Cx43 in HeLa cells induced a significant decrease in proliferation. It is therefore suggested that plasma membrane localization and formation of channels are not required for growth inhibition by Cx43, and that nuclear localization of CT-Cx43 may exert effects on gene expression and growth.

structure-function cell proliferation gap junctions nucleus 


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Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  • Xitong Dang
    • 1
  • Bradley W. Doble
    • 1
  • Elissavet Kardami
    • 1
  1. 1.Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, and Department of PhysiologyUniversity of ManitobaWinnipegCanada

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