ISSN:
1432-072X
Schlagwort(e):
Chemotaxis
;
Bacillus subtilis
;
Motility
;
Valinomycin
;
Nigericin
;
Lipophilic cations
;
Methylation
;
Hyperpolarizing wave
;
Ion gate
;
Proton-motive force
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Abstract The effects of nigericin, valinomycin and some lipophilic cations on the motile behavior of non-starved and methionine-starved Bacillus subtilis cells were studied. For valinomycin and nigericin a quantitative relationship between the flux in the proton-motive force and the duration of the twiddle response was found. Lipophilic cations bind to the ion gate controlling the twiddle frequency and thereby cause the cells to swim smoothly. To explain the transmission of the chemotactic signal a model is given in which receptors, a hyperpolarizing wave, an ion gate and two methylation sites, viz. methyl-accepting chemotaxis proteins and a further methylation site (MT), play a role. For the transmission of the signal caused by an attractant both the hyperpolarizing wave and an interaction between receptor and methylation site (MT) are needed. The methyl-accepting chemotaxis proteins are involved in the adaptation/deadaptation to altered levels of attractant. Artificial changes in the proton-motive force act directly on the ion gate, which finally controlls the twiddle frequency of the cells.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00408727
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