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Vacuolar H + ‐ATPase Domains Are Transported Separately in Axons and Assemble in Torpedo Nerve Endings
Author(s) -
Morel Nicolas,
Gérard Valérie,
Shiff Gad
Publication year - 1998
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1998.71041702.x
Subject(s) - torpedo , protein subunit , vanadate , atpase , axoplasmic transport , free nerve ending , biophysics , membrane , chemistry , biology , anatomy , biochemistry , receptor , enzyme , acetylcholine receptor , gene
Torpedo electric organ synaptosomes possess a typical vacuolar H + ‐ATPase (V‐ATPase), inhibited by concanamycin A and insensitive to vanadate, made of the association of a catalytic soluble sector V 1 to a membrane domain V 0 . In the electric nerves, the 57‐kDa subunit B of the V 1 sector was transported to the nerve endings by the slow axonal flow and did not accumulate upstream from an axonal block. In contrast, a 500% accumulation of the 15‐kDa subunit c of the V 0 membrane domain was observed, demonstrating that this subunit is conveyed by the fast axonal anterograde transport. After velocity sedimentation of solubilized nerve proteins, the 57‐ and 15‐kDa subunits were recovered in different complexes corresponding, respectively, to the V 1 and V 0 domains. No fully assembled V‐ATPase was detected. It is concluded that V 1 and V 0 domains of V‐ATPase are transported separately in axons, at different rates, and that they only associate once arrived in nerve endings to form the active V‐ATPase.