Proteolysis of tau by calpain.
The calpain-induced proteolysis of tau associated with twice-cycled microtubules or from a total brain heat-stable fraction was studied. Twice-cycled microtubule tau was rapidly hydrolyzed by calpain. In contrast, tau purified from the total brain heat-stable fraction was very resistant to degradation by calpain. These results clearly demonstrate that there are at least 2 populations of tau in the brain based on calpain-sensitivity, a calpain-sensitive form that is associated with microtubules and a calpain-resistant form that may represent another population of tau in the brain.
Johnson
G V
GV
Department of Neurology, University of Alabama, Birmingham 35294.
Jope
R S
RS
Binder
L I
LI
D000818:Animals; D001921:Brain / Q000378:metabolism; D002154:Calpain / Q000378:metabolism*; D002417:Cattle; D015151:Immunoblotting; D007700:Kinetics; D008869:Microtubule-Associated Proteins / Q000302:isolation & purification / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D016875:tau Proteins
D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; D016875:tau Proteins; D002154:Calpain