M. Terashima et al., ADP-ribosylation of tubulin by chicken NAD-arginine ADP-ribosyltransferasesuppresses microtubule formation, J NUTR SC V, 45(4), 1999, pp. 393-400
We obtained evidence that tubulin and actin, two major cytoskeletal protein
s, are preferentially ADP-ribosylated in the bovine brain cytosol by NAD-ar
ginine ADP-ribosyltransferase purified from chicken polymorphonuclear leuko
cytes. ADP-ribosylation of tubulin almost completely blocked self-assembly
of the protein. The stoichiometry of ADP-ribose incorporation into unassemb
led and assembled tubulin was 6 and 2 mol/mol of tubulin, respectively. The
se findings suggest that sites of ADP-ribosylation in the unassembled tubul
in molecule are crucial for tubulin assembly, and that covalently attached
ADP-ribose moieties interfere with tubulin interaction by steric hindrance
or conformational change. Thus, ADP-ribosylation may be involved in cytoske
letal organization in the brain via the modification of tubulin.