TY - JOUR
T1 - Membrane-derived oligosaccharides affect porin osmoregulation only in media of low ionic strength
AU - Geiger, O.
AU - Russo, F. D.
AU - Silhavy, T. J.
AU - Kennedy, E. P.
PY - 1992
Y1 - 1992
N2 - Gram-negative bacteria grown under conditions of low osmolarity accumulate significant amounts of periplasmic glucans, membrane-derived oligosaccharides (MDO) in Escherichia coli and cyclic glucans in members of the family Rhizobiaceae. It was reported previously (W. Fiedler and H. Rotering, J. Biol. Chem. 263:14684-14689, 1988) that mdoA mutants unable to synthesize MDO show a number of altered phenotypes, among them a decreased expression of OmpF and an increased expression of OmpC, when grown in a Bacto Peptone medium of low osmolarity and low ionic strength. Although we confirm the findings of Fiedler and Rotering, we find that the regulation of OmpF and OmpC expression in mdoA mutants is normal in cells grown on other low- osmolarity media, eliminating the possibility that MDO itself might control porin expression. Our data suggest that a certain minimal ionic strength in the periplasm is needed for normal porin regulation. In media containing very low levels of salt, this may be contributed by anionic MDO.
AB - Gram-negative bacteria grown under conditions of low osmolarity accumulate significant amounts of periplasmic glucans, membrane-derived oligosaccharides (MDO) in Escherichia coli and cyclic glucans in members of the family Rhizobiaceae. It was reported previously (W. Fiedler and H. Rotering, J. Biol. Chem. 263:14684-14689, 1988) that mdoA mutants unable to synthesize MDO show a number of altered phenotypes, among them a decreased expression of OmpF and an increased expression of OmpC, when grown in a Bacto Peptone medium of low osmolarity and low ionic strength. Although we confirm the findings of Fiedler and Rotering, we find that the regulation of OmpF and OmpC expression in mdoA mutants is normal in cells grown on other low- osmolarity media, eliminating the possibility that MDO itself might control porin expression. Our data suggest that a certain minimal ionic strength in the periplasm is needed for normal porin regulation. In media containing very low levels of salt, this may be contributed by anionic MDO.
UR - http://www.scopus.com/inward/record.url?scp=0026565869&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026565869&partnerID=8YFLogxK
U2 - 10.1128/jb.174.4.1410-1413.1992
DO - 10.1128/jb.174.4.1410-1413.1992
M3 - Comment/debate
C2 - 1370954
AN - SCOPUS:0026565869
SN - 0021-9193
VL - 174
SP - 1410
EP - 1413
JO - Journal of bacteriology
JF - Journal of bacteriology
IS - 4
ER -