The Bacterial Cytoskeleton

Abstract

SUMMARY In recent years it has been shown that bacteria contain a number of cytoskeletal structures. The bacterial cytoplasmic elements include homologs of the three major types of eukaryotic cytoskeletal proteins (actin, tubulin, and intermediate filament proteins) and a fourth group, the MinD-ParA group, that appears to be unique to bacteria. The cytoskeletal structures play important roles in cell division, cell polarity, cell shape regulation, plasmid partition, and other functions. The proteins self-assemble into filamentous structures in vitro and form intracellular ordered structures in vivo. In addition, there are a number of filamentous bacterial elements that may turn out to be cytoskeletal in nature. This review attempts to summarize and integrate the in vivo and in vitro aspects of these systems and to evaluate the probable future directions of this active research field.

Caspase-2 is required for cell death induced by cytoskeletal disruption

“…In order for cells to maintain cellular integrity, a dynamic balance must exist between actin and microtubule filaments. Actin maintains cellular shape, form cytoplasmic projections, regulates motility and facilitates signal transductions (Gourlay and Ayscough, 2005;Shi and Rothfield, 2006). Microtubules are involved in intracellular transport and play a role in regulation of mitotic spindle.…”

Duplication and segregation of the actin (MreB) cytoskeleton during the prokaryotic cell cycle

“…5A) (20,21). In the first known step in this sequence, FtsZ assembles into an annular structure (the Z-ring) that is thought to act as a scaffold for subsequent introduction of the other septasomal proteins (7,22).…”

“…The MreB cytoskeleton has been implicated in several cellular processes, including chromosome segregation, regulation of cell shape, and determination of cell polarity (reviewed in ref. 7).…”

RodZ, a component of the bacterial core morphogenic apparatus

“…In bacteria, some cell shape factors are limited to certain species or subsets, such as teichoic acids in gram-positive bacteria or crescentin in Caulobacter crescentus. However, there is also a core morphogenic apparatus composed of proteins with a broad, more universal function, and among them, the cytoskeleton plays a central role (1)(2)(3). This apparatus primarily dictates cell shape by topological control of cell growth.…”