| David,
V., Gouin, E., Van Troys, M., Grogan, A., Segal, A. W., Ampe, C. &
Cossart, P. (1998) Identification of cofilin, coronin, Rac and capZ in
actin tails using a Listeria affinity approach. J.Cell Sci.
111, 2877-2884.
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Abstract.
Actin assembly is involved in cell motility and intracellular movement
of Listeria monocytogenes. Induction of Listeria
actin tails is mediated by the surface protein ActA. The
N-terminal domain of ActA is sufficient for this function.
Cell components known to play a role in the actin-based motility
of Listeria are VASP (vasodilatator-stimulated phosphoprotein),
the multiprotein Arp2/3 complex and cofilin. VASP interacts with
the central domain of ActA. Proteins interacting with the
N-terminal domain of ActA have not been identified. To
identify novel host cell components of ActA-induced actin
tails, we used bovine brain extracts and an affinity approach
with Listeria as matrix. Several known components of Listeria
tails were isolated including VASP, Arp3 and cofilin. Cofilin was
identified by peptide sequencing, and cofilin recruitment and Listeria
tail length were found to be pH-dependent, in agreement with
its recently reported role in enhancing actin filament
turnover. In addition, three proteins not previously known to
be associated with Listeria tails, coronin, Rac and
capZ, were identified in our affinity approach. In infected
cells, the localization of the identified proteins was studied by immunofluorescence.
Our findings suggest that these latter proteins, which are
known to play critical roles in cellular actin rearrangements, may also
be involved in the dynamics of Listeria-induced actin
assembly. |
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