Visualization of membrane domains in Escherichia coli.
Bacterial membrane and nucleoids were stained concurrently by the lipophilic styryl dye FM 4-64 [N-(3-triethylammoniumpropyl)-4-(6-(4-(diethylamino)phenyl) hexatrienyl)pyridinium dibromide] and 4',6-diamidino-2-phenylindole (DAPI), respectively, and studied using fluorescence microscopy imaging. Observation of plasmolysed cells indicated that FM 4-64 stained the inner membrane preferentially. In live Escherichia coli pbpB cells and filaments, prepared on wet agar slabs, an FM 4-64 staining pattern developed in the form of dark bands. In dividing cells, the bands occurred mainly at the constriction sites and, in filaments, between partitioning nucleoids. The FM 4-64 pattern of dark bands in filaments was abolished after inhibiting protein synthesis with chloramphenicol. It is proposed that the staining patterns reflect putative membrane domains formed by DNA-membrane interactions and have functional implications in cell division.
Fishov
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Department of Life Sciences, Ben-Gurion University of the Negev, PO Box 653, Beer-Sheva 84105, Israel. fishov@bgumail.bgu.ac.il
Woldringh
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D001665:Binding Sites; D002455:Cell Division; D002462:Cell Membrane / Q000648:ultrastructure; D004926:Escherichia coli / Q000648:ultrastructure*; D005456:Fluorescent Dyes / Q000378:metabolism; D007211:Indoles / Q000378:metabolism; D008856:Microscopy, Fluorescence / Q000379:methods; D010743:Phospholipids / Q000378:metabolism; D011726:Pyridinium Compounds / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000378:metabolism
C092350:FM 4-64; D005456:Fluorescent Dyes; D007211:Indoles; D010743:Phospholipids; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; C007293:DAPI