Rat brain synaptic vesicles are devoid of Mg2+-ATPase activity and contain beta-amyloid precursor protein.
Rat brain synaptic vesicles (SVs) isolated by gel filtration on Sephacryl S-500 had little Mg2+(H+)-ATPase activity, though it was identified by Western blots with antibodies against the H+-ATPase A-subunit and other vesicle proteins. In contrast, tyrosine hydroxylase and dopa decarboxylase activities in the SVs were substantial, suggesting that the absence of Mg2+(H+)-ATPase activity was not due to inactivation during isolation but rather to the nature of the SVs. The vesicle component reactive to H+-ATPase antibody was also identified in the synaptosomal cytosol, so the antibody for the A-subunit seemed unnecessary to detect H+-ATPase. The SVs contained beta-amyloid precursor protein of approximately 100 kDa. Based on these observations, SVs without Mg2+(H+)-ATPase seemed to play a role(s) in the delivery of cytoplasmic and plasma membrane proteins to nerve terminals as well as in neurotransmission.
Tsudzuki
Toshihiro
T
Department of Biochemistry I, School of Medicine, Nagoya City University, Kawasumi 1, Mizuho-ku, Nagoya 467-8601, Japan. tsudzuki@sunprom.med.nagoya-cu.ac.jp
D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology; D002850:Chromatography, Gel; D004296:Dopa Decarboxylase / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D008297:Male; D006180:Proton-Translocating ATPases / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D013572:Synaptic Vesicles / Q000737:chemistry*; D013574:Synaptosomes / Q000201:enzymology; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis
D016564:Amyloid beta-Protein Precursor; D014446:Tyrosine 3-Monooxygenase; D017301:Ca(2+) Mg(2+)-ATPase; D006180:Proton-Translocating ATPases; D004296:Dopa Decarboxylase