Cell-to-cell communication through gap junctions exists in most animal cells and is essential for many important biological processes including rapid transmission of electric signals to coordinate contraction of cardiac and smooth muscle, the intercellular propagation of Ca2+ waves and synchronization of physiological processes between adjacent cells within a tissue. Recent studies have shown that connexins (Cx) can have either direct or indirect interactions with other plasma membrane ion channels or membrane transport proteins with important functional consequences. For example, in tissues most severely affected by cystic fibrosis (CF), activation of the CF Transmembrane Conductance Regulator (CFTR) has been shown to influence connexin function. Moreover, a direct interaction between Cx45.6 and the Major Intrinsic Protein/AQP0 in lens appears to influence the process of cell differentiation whereas interactions between aquaporin 4 (AQP4) and Cx43 in mouse astrocytes may coordinate the intercellular movement of ions and water between astrocytes. In this review, we discuss evidence supporting interactions between Cx and membrane channels/transporters including CFTR, aquaporins, ionotropic glutamate receptors, and between pannexin1, another class of putative gap-junction-forming proteins, and Kvβ3, a regulatory β-subunit of voltage gated potassium channels. Although the precise molecular nature of these interactions has yet to be defined, their consequences may be critical for normal tissue homeostasis.
Bibliographical noteFunding Information:
We thank Suzanne Duperret for secreterial assistance. This work was supported by grants from the Swiss National Science Foundation (#3100-067120.01) and the French Association “Vaincre la Mucoviscidose” (to MC). This work was also partially supported by grants from the NIH (GM20113 to CP and AI50494 and DK74010 to SMO). BAK is member of the National Council of Research of Argentina (CONICET).
Copyright 2008 Elsevier B.V., All rights reserved.
- Glutamate receptors