Single channel behavior of recombinant beta 2 gap junction connexons reconstituted into planar lipid bilayers.
The beta 2 gap junction protein (Cx26) was expressed in an insect cell line by infection with a baculovirus vector containing the rat beta 2 cDNA. Isolated beta 2 gap junction connexons were reconstituted into planar lipid bilayers. Single channel activity was observed with a unitary conductance of 35-45 pS in 200 mM KCl. Channels with conductance values of 60 pS and 90-110 pS also coexisted with the lower conducting channel suggesting that there are channels with different conductance properties within a population of connexons. Channel activity was observed at voltages of up to 150 mV. Furthermore, the characterization of these channel properties from the beta 2 connexons that were generated by this heterologous expression system has provided the basis for identifying an endogenous beta 2 connexon channel in material reconstituted from native rat liver gap junctions.
Buehler
L K
LK
Department of Cell Biology, Scripps Research Institute, La Jolla, California 92037, USA.
Stauffer
K A
KA
Gilula
N B
NB
Kumar
N M
NM
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D002784:Cholesterol; D000072259:Connexin 26; D017630:Connexins / Q000096:biosynthesis / Q000302:isolation & purification / Q000502:physiology*; D004553:Electric Conductivity; D017629:Gap Junctions / Q000502:physiology*; D015640:Ion Channel Gating; D007473:Ion Channels / Q000302:isolation & purification / Q000502:physiology*; D008051:Lipid Bilayers; D008099:Liver / Q000502:physiology*; D008564:Membrane Potentials; D010714:Phosphatidylethanolamines; D010718:Phosphatidylserines; D011336:Probability; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D018411:Spodoptera; D014162:Transfection
D017630:Connexins; C000607044:Gjb2 protein, rat; D007473:Ion Channels; D008051:Lipid Bilayers; D010714:Phosphatidylethanolamines; D010718:Phosphatidylserines; D011994:Recombinant Proteins; C057561:1-palmitoyl-2-oleoylphosphatidylethanolamine; D000072259:Connexin 26; C050294:1-palmitoyl-2-oleoylglycero-3-phosphoserine; D002784:Cholesterol