Udorn Junthorn. Single particle tracking for MinE protein oscillations in Escherichia coli : dynamics and localization. Master's Degree(Physics ). Mahidol University. : Mahidol University, 2008.
Single particle tracking for MinE protein oscillations in Escherichia coli : dynamics and localization
Abstract:
The dynamics of the MinE proteins has been recognized to play an important
role in accurate placement of the septum during cell division. In this work, single
particle tracking (SPT) was, for the first time, applied to investigate the GFP:MinE
protein behavior in E. coli in terms of dynamics and localization. The results of the
oscillating trajectory and speed can be classified according to the space and time
scales of dynamic events into two types: flight events and switching events. The
switching events mostly occur near polar zones while the flight events take place
between the switching events in the space between the polar zones. From quantitative
analysis for E. coli strain RC1/pSY1083G, it was found that the switching events
occur during turning at the poles with an average switching speed of 2.16 ± 0.68 μm/s
and the flight events occur with an average flight speed of 0.23 ± 0.08 μm/s. The SPT
data monitored from the dividing E. coli samples demonstrated an oscillation period of
the MinE proteins between the two poles with an average of 270 ± 120 seconds in 5.08
± 0.82 μm length. The tendency of MinEs oscillation period depends on the cell
length. The agreements between the findings, particularly the localization and those
from previous studies are discussed. These results demonstrate the benefits of applying
SPT to investigate the oscillations of targeted proteins not only in a quantitative, but
also in a qualitative one.