Apparently irreversible GTP hydrolysis attends tubulin self-assembly.
The pathway of GTP hydrolysis associated with microtubule polymerization was investigated using an assay of intermediate 18O-exchange reactions. Under a variety of conditions influencing tubulin self-assembly, GTP was hydrolyzed without any evidence of multiple reversals characteristic of reversible phosphoanhydride-bond cleavage. These results also accord with published findings that ATP hydrolysis during actin polymerization fails to display intermediate exchange reactions [Carlier, M. F., Pantaloni, D., Evans, J. A., Lambooy, P. K., Korn, E. D. and Webb, M. R. (1988) FEBS Lett. 235, 211-214].
Angelastro
J M
JM
Department of Biochemistry and Molecular Biology, University of Florida.
Purich
D L
DL
D004735:Energy Transfer; D020558:GTP Phosphohydrolases / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism*; D006868:Hydrolysis; D008870:Microtubules / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism*
D010710:Phosphates; D014404:Tubulin; D006160:Guanosine Triphosphate; D020558:GTP Phosphohydrolases; D010100:Oxygen