ADP-ribosylated actin as part of the actin monomer pool in rat brain.
Mono-ADP-ribosylation in mammals is poorly understood. In this study, we found mono-ADP-ribosylated actin in rat brains. Mono-ADP-ribosylated actin by ADP-ribosyltransferase or nonenzymatic reaction was shown at a different position from the unmodified actin in the isoelectrical focusing. High-pressure liquid chromatography utilizing a reverse phase (ODS) column separated ADP-ribosylated actin from unmodified actin. In the two-dimensional gel electrophoreses and high-pressure liquid chromatography, the endogenously ADP-ribosylated actin was detected in the supernatant fraction from the rat brain extract, where a nonpolymerizing actin was present after removal of the polymerizing actin. The concentration of NAD and ADP-ribose, after microwave irradiation, was 220 nmol and 150 nmol/g of rat brain tissue. Actin ADP-ribosylated by purified ADP-ribosyltransferase failed to form actin filaments after the addition of Mg2+. Actin ADP-ribosylated by the nonenzymatic reaction could polymerize with the addition of Mg2+. The enzymatically modified actin could form actin filaments after treatment with ADP-ribosylhydrolase but not after treatment with phosphodiesterase. These results suggest that ADP-ribosylated actin by enzymatic or nonenzymatic reaction is one of the sequestering factors in actin-actin binding and is a part of the actin pool in the rat brain.
Tsuyama
S
S
Department of Veterinary Science, Osaka Prefecture University, Japan.
Inoue
Y
Y
Tanaka
M
M
D000199:Actins / Q000737:chemistry*; D000246:Adenosine Diphosphate Ribose; D000818:Animals; D001923:Brain Chemistry; D002851:Chromatography, High Pressure Liquid; D019281:Dimerization; D015180:Electrophoresis, Gel, Two-Dimensional; D051381:Rats
D000199:Actins; D000246:Adenosine Diphosphate Ribose