FtsZ and the division of prokaryotic cells and organelles

Abstract

Binary fission of many prokaryotes as well as some eukaryotic organelles depends on the FtsZ protein, which self-assembles into a membrane-associated ring structure early in the division process. FtsZ is homologous to tubulin, the building block of the microtubule cytoskeleton in eukaryotes. Recent advances in genomics and cell-imaging techniques have paved the way for the remarkable progress in our understanding of fission in bacteria and organelles.Duplication of cells occurs by the division of a mother cell into two daughter cells. This process, known as cytokinesis, provides the force to split cells and is spatially regulated to faithfully partition the genetic material. The cytoskeleton has a crucial role in cytokinesis. In animal and fungal cells, a medial ring of actin and myosin, helped by other proteins, contracts to divide the cell. Plant cells use a cell plate, and are guided by actin filaments and microtubules. Prokaryotes, which include bacteria and archaea, possess homologues of eukaryotic cytoskeletal proteins. Most prokaryotes use a tubulin homologue, a protein known as FtsZ, to divide. Eukaryotic organelles such as chloroplasts and mitochondria evolved from bacteria, and all chloroplasts and some mitochondria use FtsZ to divide.FtsZ is thought to be the first protein to localize to the site of future division in bacteria 1 , and it assembles into what is known as the Z ring (FIG. 1). In Escherichia coli, the Z ring recruits at least ten other proteins, all of which are required for the progression and completion of cytokinesis 2 , as will be discussed below. Whereas the cytokinetic apparatus in eukaryotic cells and even organelles can be observed directly in stained thin sections by transmission electron microscopy, the Z ring and its associated factors are not detectable by these methods. This is probably because the protein machinery is largely membrane bound and resides in a densely populated cytoplasmic environment. However, the development of green fluorescent protein (GFP) fusion and improved immunofluorescence techniques over the past 10 years have been crucial in allowing the first direct visualization of many cellular components and their dynamics. For example, using GFP fusions, the dynamics of the Z ring and other components of the cell-division protein machinery can now be visualized in living bacterial cells. The combination of these new cytological tools with genomics and the Competing interests statementThe author declares no competing financial interests. HHS Public Access Author Manuscript Author ManuscriptAuthor ManuscriptAuthor Manuscript already powerful genetics of several model systems have spurred rapid progress in our understanding of the molecular cell biology of bacteria and eukaryotic organelles. This review will discuss how the recent revolutions in genomics and cell biology have provided new evolutionary and mechanistic insights into how bacterial cells and organelles divide. The FtsZ family of proteins Conservation of FtsZFtsZ is a highly conserved protein ...

GFP‐targeting allows visualization of the apicoplast throughout the life cycle of live malaria parasites

“…In plants, the process of chloroplast division seemingly begins when Ftsz proteins form a ring structure within the chloroplast stroma that leads to constriction of the organelle, as reviewed in Margolin (2005). An array of proteins then become associated with the constrictions, with the final fission event being carried out by a dynamin protein, which encircles the constricted region and constricts it further, leading to organelle division.…”

“…Our understanding of the division of endosymbiotic organelles is most advanced in the case of the chloroplast of higher plants. Here, Ftsz proteins form a ring structure within the stroma of the chloroplast, seemingly constricting the organelle in a drawstring action (reviewed in Margolin, 2005). Other proteins, including dynamin, are then recruited to the constricted regions of the chloroplast and this leads to fission of the organelle (Gao et al, 2003;Miyagishima et al, 2003).…”

Dynamics of bacterial cytoskeletal elements

“…In all bacteria analysed so far, FtsZ forms a ring (called Z-ring) at the cell centre (or slightly off centre in some bacteria that divide asymmetrically) ( Fig. 1), which sets off cell division (for recent reviews providing comprehensive coverage of the field of bacterial cytokinesis see [Margolin, 2005;Dajkovic and Lutkenhaus, 2006;Harry et al, 2006]). Some mollicutes (e.g., Mycoplasma species) and the two bacterial branches of Planctomyces and of Clamydia, whose members are renowned for their very unusual subcellular features, lack an obvious ftsZ gene, all other bacteria analysed so far and the Euryarchaeota branch of the archaea contain the gene and thus share a common basic mode of cell division (the other branch of the archaea, the Crenarchaeota may have an ESCRT III like division system [Lindas et al, 2008;Samson et al, 2008]).…”

“…Some mollicutes (e.g., Mycoplasma species) and the two bacterial branches of Planctomyces and of Clamydia, whose members are renowned for their very unusual subcellular features, lack an obvious ftsZ gene, all other bacteria analysed so far and the Euryarchaeota branch of the archaea contain the gene and thus share a common basic mode of cell division (the other branch of the archaea, the Crenarchaeota may have an ESCRT III like division system [Lindas et al, 2008;Samson et al, 2008]). FtsZ genes are also present in the plant chloroplast and in mitochondria of some simple eukaryotes, where the gene products are essential for the division of the organelles [Margolin, 2005]. The moss Physcomitrella patens even contains a family of 5 ftsZ related genes that appear to set up a cytoskeleton within the plastids [Osteryoung and Nunnari, 2003].…”

Phenylpropanoids inhibit protofilament formation of Escherichia coli cell division protein FtsZ

“…The septal ring constricts in concert with septal progression, culminating in complete disassembly as soon as it matures. Inhibition of this central protein perturbs the formation of the Z-ring and bacterial cytokinesis (Margolin, 2005). FtsZ has become an attractive target, due to its evolutionary distance from eukaryotic tubulin.…”