Dissecting a Novel Mechanism of Cell Motility

Obiettivo

Cell motility is essential for many biological processes, including development and pathogenesis. Thus, the
molecular mechanisms underlying this process have been intensively studied in many cell systems, for
example, leukocytes, amoeba and even bacteria. Intriguingly, bacteria are also able to move across solid
surfaces (gliding motility) like eukaryotic cells by a process that has remained largely mysterious. The
emergence of bacterial cell biology: the discovery that the bacterial cell also has a dynamic cytoskeleton and
specialized subcellular regions now provides new research angles to study the motility mechanism. Using
cell biology approaches, we previously suggested that the mechanism may be akin to acto-myosin-based
motility in eukaryotic cells and proposed that bacterial focal adhesion complexes also power locomotion. In
this project, we propose two complementary research axes to define both the mechanism and its spatial
regulation in the cell at molecular resolution.
Using the model motility bacterium Myxococcus xanthus, we first propose to develop a “toolbox” of
biophysical and cell biology assays to analyze the motility process. Specifically, we will construct a Traction
Force Microscopy assay designed to image the motility forces directly by live moving cells and use
microfluidics to quantitate the secretion of a mucus that may participate directly in the motility process.
These assays, combined with a newly developed laser trap system to visualize dynamic focal adhesions in
the cell envelope, will be instrumental not only to define new features of the motility process, but also to
study the function of novel motility genes which may encode the components of the elusive motility engine.
This way, we hope to establish the mechanism and structure function relationships within an entirely novel
motility machinery.
In a second part, we propose to investigate the mechanism that controls a polarity switch, allowing M.
xanthus cells to change their direction of movement. We have previously shown that dynamic motility
protein pole-to-pole oscillations convert the initial leading cell pole into the lagging pole. Here, we propose
that like in a eukaryotic cells, a bacterial counterpart of small GTPases of the Ras superfamily, MglA
controls the polarity cycle. To test this hypothesis, we will study both the MglA upstream regulation and the
MglA downstream effectors. We thus hope to establish a model of dynamic polarity control in a bacterial

Campo scientifico

Meccanismo di finanziamento

ERC-SG - ERC Starting Grant

Istituzione ospitante

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS

Contributo UE

€ 1 437 693,00

Indirizzo

RUE MICHEL ANGE 3
75794 Paris
Francia

Regione

Ile-de-France Ile-de-France Paris

Tipo di attività

Research Organisations

Ricercatore principale

Tâm Mignot (Dr.)

Contatto amministrativo

Béatrice Saint-Cricq (Ms.)

Collegamenti

Contatta l’organizzazione Sito web

Costo totale

Nessun dato

Beneficiari (1)