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Immunolabelling of the presynaptic membrane of Torpedo electric organ nerve terminals with an antiserum towards the acetylcholine releasing protein mediatophore
Author(s) -
Brochier Guy,
Israel Maurice,
Lesbats Bernard
Publication year - 1993
Publication title -
biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 85
eISSN - 1768-322X
pISSN - 0248-4900
DOI - 10.1016/0248-4900(93)90125-x
Subject(s) - torpedo , immunogold labelling , biology , synaptic vesicle , immunocytochemistry , acetylcholine , protein subunit , microbiology and biotechnology , postsynaptic potential , antiserum , membrane protein , biochemistry , membrane , antigen , acetylcholine receptor , antibody , vesicle , immunology , endocrinology , gene , receptor
Summary— Mediatophore is a nerve terminal membrane protein purified from Torpedo electric organ on its ability to translocate acetylcholine upon calcium action. An antiserum able to immunoprecipitate mediatophore activity was used to study the subcellular distribution of this protein. The presynaptic membrane exhibited a strong and discontinuous immunogold labelling, especially at the active zone where ACh is thought to be released. Two antigens were recognized on immunoblots of synaptosomal membranes: the 15‐kDa subunit of mediatophore and a 14‐kDa membrane protein that has a wide non‐neuronal distribution. Antibodies purified from the serum on native mediatophore and monospecific towards the 15‐kDa antigen still gave a high presynaptic membrane localized labelling. In addition, a few 14‐kDa protein sites were present at the active zone. The Schwann cell finger interposed between the presynaptic membrane and the postsynaptic arch also exhibited the 14‐kDa antigen raising the question of a possible interaction of mediatophore with the 14‐kDa protein originating from the Schwann cell.