S. Arnould et al., Acylation stabilizes a protease-resistant conformation of protoporphyrinogen oxidase, the molecular target of diphenyl ether-type herbicides, P NAS US, 96(26), 1999, pp. 14825-14830
Citations number
49
Categorie Soggetti
Multidisciplinary
Journal title
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Protein acylation is an important way in which a number of proteins with a
variety of functions are modified. The physiological role of the acylation
of cellular proteins is still poorly understood. Covalent binding of fatty
acids to nonintegral membrane proteins is thought to produce transient or p
ermanent enhancement of the association of the polypeptide chains with biol
ogical membranes. In this paper, we investigate the functional role for the
palmitoylation of an atypical membrane-bound protein, yeast protoporphyrin
ogen oxidase, which is the molecular target of diphenyl ether-type herbicid
es. Palmitoylation stabilizes an active heat- and protease-resistant confor
mation of the protein. Palmitoylation of protoporphyrinogen oxidase has bee
n demonstrated to occur in vivo both in yeast cells and in a heterologous b
acterial expression system, where it may be inhibited by cerulenin leading
to the accumulation of degradation products of the protein. The thiol ester
linking palmitoleic acid to the polypeptide chain was shown to be sensitiv
e to hydrolysis by hydroxylamine and also by the widely used serine-proteas
e inhibitor phenylmethylsulfonyl fluoride.