Purification and cDNA cloning of mouse BM89 antigen shows that it is identical with the synaptic vesicle protein synaptophysin.
The BM89 antigen, first identified in porcine brain by means of a monoclonal antibody, is a neuron-specific molecule widely distributed in the mammalian central and peripheral nervous system (Merkouri and Matsas: Neuroscience 50:53-68, 1992). Here we describe the purification of BM89 antigen from porcine and mouse brain by immunoaffinity chromatography using, respectively, the previously described BM89 monoclonal antibody which belongs to the IgM class and a specific polyclonal antibody generated in the present study. This antibody was also used for the cDNA cloning of the BM89 antigen from mouse brain. cDNA sequencing revealed that the mouse BM89 antigen is identical with the synaptic vesicle protein synaptophysin which is implicated in the control of regulated exocytosis and neurotransmitter release. Mouse BM89 antigen/synaptophysin exhibits, except for one extra amino acid, 100% identity with rat synaptophysin and substantial sequence identity with bovine (92.5% identity) and human (94.8% identity) synaptophysin, but only 59.8% identity with Torpedo synaptophysin. Northern and Western blot analyses confirmed that the mouse BM89 antigen/synaptophysin is expressed only in neural tissues.
Gaitanou
M
M
Department of Biochemistry, Hellenic Pasteur Institute, Athens, Greece.
Mamalaki
A
A
Merkouri
E
E
Matsas
R
R
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001923:Brain Chemistry; D002417:Cattle; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics*; D015723:Gene Library; D006801:Humans; D051379:Mice / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D051381:Rats; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013552:Swine / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016708:Synaptophysin / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D014101:Torpedo
D018076:DNA, Complementary; D016708:Synaptophysin