Connexin-43 Hemichannels Opened by Metabolic Inhibition

Connexin 43 hemichannels are permeable to ATP.

Astrocytes are electrically nonexcitable cells that communicate by means of Ca(2+) signaling. Long-distance intercellular Ca(2+) waves are initiated by release of ATP and activation of purinergic receptors on nearby cells. Previous studies have implicated connexin 43 (Cx43) in ATP release, but definitive proof that ATP exits through Cx43 hemichannels does not exist. Here, through several altern...

Connexin 43 hemichannels and intracellular signaling in bone cells

Cell function and survival are controlled by intracellular signals, and modulated by surrounding cells and the extracellular environment. Connexin channels participate in these processes by mediating cell-to-cell communication. In bone cells, gap junction channels were detected in the early 1970s, and are present among bone resorbing osteoclasts, bone forming osteoblasts, and osteocytes - matur...

Connexin 43 Hemichannels and Pharmacotherapy of Myocardial Ischemia Injury

Gating and regulation of connexin 43 (Cx43) hemichannels.

Connexin 43 (Cx43) nonjunctional or "unapposed" hemichannels can open under physiological or pathological conditions. We characterize hemichannels comprised of Cx43 or Cx43-EGFP (Cx43 with enhanced GFP fused to the C terminus) expressed in HeLa cells. Channel opening was induced at potentials greater than +60 mV. Open probability appeared to be very low. No comparable opening was detected in th...

Change in permeant size selectivity by phosphorylation of connexin 43 gap-junctional hemichannels by PKC.

Gap-junctional channels, permeable to large hydrophilic solutes of up to M(r) approximately 1,000, are responsible for cell-to-cell communication. Phosphorylation of connexin 43 (Cx43) by PKC abolishes the permeability of gap-junctional channels and hemichannels to large hydrophilic solutes, but not to small inorganic ions. Here, we report on a methodology to produce purified hemichannels of co...