microbiology, Vol 141, 3119-3126, Copyright © 1995 by Society for General Microbiology
Starvation yields a drastic decrease in outer-membrane permeability to a periplasmic foreign protein in Myxococcus xanthus
K Laval-Favre, B Letouvet-Pawlak, S Barray and JF Guespin-Michel
Equipe de Genetique Bacterienne, URA 203 CNRS, Faculte des Sciences de Rouen, Mont-Saint-Aignan, France.
A recombinant Myxococcus xanthus strain was constructed that constitutively
produces two proteins from Escherichia coli, the cytoplasmic
beta-galactosidase and the periplasmic pH 2.5 acid phosphatase (AppA
protein). We have previously shown that during vegetative growth, AppA
protein is partly accumulated in the periplasm of M. xanthus and partly
released into the medium. We demonstrate here that during
starvation-induced development, release of periplasmic AppA protein to the
medium did not occur over a period of 20 h. This was coincident with, but
not caused by, the arrest of the synthesis of the foreign proteins. We have
shown that this lack of secretion could be attributed to starvation per se
and did not depend on the ability of the cells to undergo development. Our
findings suggest that protein secretion which occurs during the first hours
of starvation-induced development might therefore take place via a
different route from that which occurs in vegetative cells.
