Cloning and in situ localization of a brain-derived porin that constitutes a large-conductance anion channel in astrocytic plasma membranes.
We have cloned a protein from bovine brain, brain-derived voltage-dependent anion channel 1 (BR1-VDAC), that is identical to a recently sequenced plasmalemmal-bound porin from human lymphocytes. mRNA hybridization indicates that BR1-VDAC is widely distributed throughout nervous and nonnervous tissues. In situ localization substantiated that the BR1-VDAC is associated with the plasmalemma of astrocytes. A monoclonal antibody that recognizes the N terminus of the BR1-VDAC protein completely blocks an astrocytic high-conductance anion channel that has electrophysiological similarities with the mitochondrial VDAC. Since the high-conductance anion channel in astrocytes has been shown to respond to hypoosmotic solutions, its molecular identification provides the basis for a better understanding of volume regulation in brain tissue.
Dermietzel
R
R
Institute of Anatomy, University of Regensburg, Germany.
Hwang
T K
TK
Buettner
R
R
Hofer
A
A
Dotzler
E
E
Kremer
M
M
Deutzmann
R
R
Thinnes
F P
FP
Fishman
G I
GI
Spray
D C
DC
D000818:Animals; D000911:Antibodies, Monoclonal; D001253:Astrocytes / Q000378:metabolism*; D001483:Base Sequence; D001667:Binding, Competitive; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D007473:Ion Channels / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D008969:Molecular Sequence Data; D018272:Porins; D051381:Rats; D050995:Voltage-Dependent Anion Channel 1; D050994:Voltage-Dependent Anion Channels
D000911:Antibodies, Monoclonal; D018076:DNA, Complementary; D007473:Ion Channels; D008565:Membrane Proteins; D018272:Porins; D050994:Voltage-Dependent Anion Channels; D050995:Voltage-Dependent Anion Channel 1