Expression of a paired helical filament tau epitope in embryonic chicken central nervous system.
Immunoblots from embryonic chicken optic lobes (midbrain) and spinal cord were found to contain different proteins with a molecular weight between 45 and 70 kDa that are recognized by monoclonal antibodies (mAbs) directed at human tau proteins. Each appears as a doublet on SDS-PAGE. The upper, slower migrating bands were recognized by AT8, a monoclonal antibody that requires a phosphorylated Ser-202, an epitope specific for abnormally phosphorylated tau of paired helical filaments (PHF-tau) in Alzheimer brains. The corresponding faster migrating bands were stained by the mAbs BT2 and tau-1, both requiring an epitope containing a non-phosphorylated Ser-202. Phosphatase treatment abolished binding of AT8 and induced an additional binding of tau-1 (and BT2) to the upper bands. Thus, the data suggest that in embryonic chicken central nervous system Ser-202 occurs in a phosphorylated and in a non-phosphorylated state in several distinct tau isoforms.
Rösner
H
H
Institute of Zoology, University of Hohenheim, Stuttgart, Germany.
Rebhan
M
M
Vacun
G
G
Vanmechelen
E
E
D000818:Animals; D000911:Antibodies, Monoclonal; D001921:Brain / Q000254:growth & development / Q000276:immunology / Q000378:metabolism; D002490:Central Nervous System / Q000378:metabolism*; D002642:Chick Embryo; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000276:immunology*; D015151:Immunoblotting; D010744:Phosphoric Monoester Hydrolases / Q000494:pharmacology; D013116:Spinal Cord / Q000254:growth & development / Q000276:immunology / Q000378:metabolism; D016875:tau Proteins / Q000096:biosynthesis* / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000939:Epitopes; D016875:tau Proteins; D010744:Phosphoric Monoester Hydrolases