Descripción del proyecto
Determinantes de la forma de las células bacterianas
En todos los organismos, el tamaño y la forma de las células desempeñan papeles cruciales en sus funciones biológicas. En las bacterias y otros microorganismos, la determinación física de la forma celular se atribuye a la pared celular de peptidoglucano, que ofrece resistencia y rigidez pero al mismo tiempo se expande y remodela dinámicamente. El equipo del proyecto RCSB, financiado por el Consejo Europeo de Investigación, pretende investigar cómo las bacterias controlan con precisión la forma y el volumen de sus células. Los investigadores se centrarán en la dinámica de la pared celular y las proteínas que intervienen en su expansión utilizando técnicas avanzadas de microscopía. En el estudio también se analizará la influencia de las señales físicas y otros factores en la regulación del volumen celular.
Objetivo
Proper cell size and shape are important for many biological functions, such as metabolism, signaling, motility, and development. This proposal addresses the fundamental question of how bacteria control their morphology and their cell volume with high precision, using the rod-like bacterium Escherichia coli as a primary model system. Bacterial cell shape is physically determined during growth by the enzymatic expansion and remodeling of the peptidoglycan (PG) cell wall, a partially ordered elastic meshwork that is the pressure-bearing component of the cell envelope. In this proposal we will address two fundamental questions:
i) How do cells physically build and remodel their macroscopically ordered cell wall to reproducibly acquire cell shape? We will thus image the dynamics of the PG cell wall and of the enzymatic and structural proteins involved in its expansion, using high-precision video fluorescence microscopy and spectroscopy. From spatio-temporal correlations measured in steady-state experiments and after physical, chemical, or biological perturbations, we will deduce how different physical cues affect and regulate cell-wall expansion.
ii) How do bacteria regulate their own cell volume, and what role does intracellular crowding play in this context? The intracellular mass density of bacteria is remarkably well conserved during growth, suggesting that cell size is regulated to maintain a constant level of intracellular crowding. Crowding has been deemed important for the regulation of volume in slowly growing mammalian cells before. Here, we will study the role of intracellular crowding, osmotic pressure, and other physiological quantities on cell-volume regulation in bacteria. Furthermore, we will use phenotypic screening and genetic approaches to identify the pathways involved in cell-volume control.
Together, this proposal addresses a fundamental question of self-organization in biology using combined approaches from physics and biology.
Ámbito científico
- natural sciencesbiological sciencesmicrobiologybacteriology
- natural sciencesbiological sciencescell biology
- natural sciencesphysical sciencesopticsmicroscopy
- natural sciencesbiological sciencesbiochemistrybiomoleculescarbohydrates
- natural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymes
Programa(s)
Régimen de financiación
ERC-STG - Starting GrantInstitución de acogida
75724 Paris
Francia