On biophysical properties and sensitivity to gap junction blockers of connexin 39 hemichannels expressed in hela cells

Abstract

© 2017 Vargas, Cisterna, Saavedra-Leiva, Urrutia, Cea, Vielma, Gutierrez-Maldonado, Martin, Pareja-Barrueto, Escalona, Schmachtenberg, Lagos, Perez-Acle and Sáez. Although connexins (Cxs) are broadly expressed by cells of mammalian organisms, Cx39 has a very restricted pattern of expression and the biophysical properties of Cx39-based channels [hemichannels (HCs) and gap junction channels (GJCs)] remain largely unknown. Here, we used HeLa cells transfected with Cx39 (HeLa-Cx39 cells) in which intercellular electrical coupling was not detected, indicating the absence of GJCs. However, functional HCs were found on the surface of cells exposed to conditions known to increase the open probability of other Cx HCs (e.g., extracellular divalent cationic-free solution (DCFS), extracellular alkaline pH, mechanical stimulus and depolarization to positive membrane potentials). Cx39 HCs were blocked by some traditional Cx HC blockers, but not by others or a pannexin1 channel blocker. HeLa-Cx39 cel