TY - JOUR
T1 - Mutual effects of MinD-membrane interaction
T2 - I. Changes in the membrane properties induced by MinD binding
AU - Mazor, Shirley
AU - Regev, Tomer
AU - Mileykovskaya, Eugenia
AU - Margolin, William
AU - Dowhan, William
AU - Fishov, Itzhak
N1 - Funding Information:
The highly professional technical assistance of Sonia Soreanu is greatly appreciated. This work was supported by grant 820/05 from the Israel Science Foundation to IF, grants R37-GM20478 and R01-GM61074 from the United States National Institutes of General Medical Sciences to WD and WM, respectively.
PY - 2008/11/1
Y1 - 2008/11/1
N2 - In Escherichia coli and other bacteria, MinD, along with MinE and MinC, rapidly oscillates from one pole of the cell to the other controlling the correct placement of the division septum. MinD binds to the membrane through its amphipathic C-terminal α-helix. This binding, promoted by ATP-induced dimerization, may be further enhanced by a consequent attraction of acidic phospholipids and formation of a stable proteolipid domain. In the context of this hypothesis we studied changes in dynamics of a model membrane caused by MinD binding using membrane-embedded fluorescent probes as reporters. A remarkable increase in membrane viscosity and order upon MinD binding to acidic phospholipids was evident from the pyrene and DPH fluorescence changes. This viscosity increase is cooperative with regards to the concentration of MinD-ATP, but not of the ADP form, indicative of dimerization. Moreover, similar changes in the membrane dynamics were demonstrated in the native inverted cytoplasmic membranes of E. coli, with a different depth effect. The mobility of pyrene-labeled phosphatidylglycerol indicated formation of acidic phospholipid-enriched domains in a mixed acidic-zwitterionic membrane at specific MinD/phospholipid ratios. A comparison between MinD from E. coli and Neisseria gonorrhea is also presented.
AB - In Escherichia coli and other bacteria, MinD, along with MinE and MinC, rapidly oscillates from one pole of the cell to the other controlling the correct placement of the division septum. MinD binds to the membrane through its amphipathic C-terminal α-helix. This binding, promoted by ATP-induced dimerization, may be further enhanced by a consequent attraction of acidic phospholipids and formation of a stable proteolipid domain. In the context of this hypothesis we studied changes in dynamics of a model membrane caused by MinD binding using membrane-embedded fluorescent probes as reporters. A remarkable increase in membrane viscosity and order upon MinD binding to acidic phospholipids was evident from the pyrene and DPH fluorescence changes. This viscosity increase is cooperative with regards to the concentration of MinD-ATP, but not of the ADP form, indicative of dimerization. Moreover, similar changes in the membrane dynamics were demonstrated in the native inverted cytoplasmic membranes of E. coli, with a different depth effect. The mobility of pyrene-labeled phosphatidylglycerol indicated formation of acidic phospholipid-enriched domains in a mixed acidic-zwitterionic membrane at specific MinD/phospholipid ratios. A comparison between MinD from E. coli and Neisseria gonorrhea is also presented.
KW - Fluorescent membrane probe
KW - Membrane domain
KW - Membrane dynamics
KW - Protein-membrane interaction
UR - http://www.scopus.com/inward/record.url?scp=54049136408&partnerID=8YFLogxK
U2 - 10.1016/j.bbamem.2008.08.003
DO - 10.1016/j.bbamem.2008.08.003
M3 - Article
C2 - 18760994
AN - SCOPUS:54049136408
SN - 0005-2736
VL - 1778
SP - 2496
EP - 2504
JO - Biochimica et Biophysica Acta - Biomembranes
JF - Biochimica et Biophysica Acta - Biomembranes
IS - 11
ER -