Transcriptional regulation of ceil division genes in Escherichia coli

Abstract

The complete Escherichia coli ftsQ coding sequence, together with part of the ftsA coding sequence, has been cloned upstream of the lacZ open reading frame in a lambda-vector (lambda JFL100). Cells which are lysogenic for lambda JFL100 transcribe the cloned lacZ from promoter(s) within the ftsQ and ftsA sequences. The level of beta-galactosidase produced is dependent on growth rate (and/or cell size) and is derepressed in an ftsA-deficient mutant. Transcription during the cell cycle is restricted to the time of cell division.

Transcription of the ftsZ gene and cell division in Escherichia coli

“…We conclude that the FtsA, FtsQ, FtsI (PBP3), and FtsZ proteins do not exert any transcriptional control on theftsZ gene, in contradiction with other reports (3,5).…”

“…In an independent study, using the same ftsZ::lacZ fusion but a different experimental system, others have recently reported that ftsZ transcription takes place only at the time of septation initiation (3). One difference between their study and the present work is the selection by these authors of small cells from a sucrose gradient to obtain a synchronous population; we are currently investigating the possible effects of osmotic shock on ftsZ expression.…”

Analysis of the effect of ppGpp on the ftsQAZ operon in Escherichia coli

“…Other estimates of the relative strength of these promoters, based on studies with transcriptional fusions (Yi et al, 1985;Wang et al, 1991;Flä rdh et al, 1997), found about 60% of the total ftsZ mRNA species started from pZ4-pZ3-pZ2-'pZ1', compared with 92% in our study (Table 4). However, the strength of several of these promoters has been shown to vary considerably with growth rate and with growth phase (Dewar et al, 1989;Aldea et al, 1990;Robin et al, 1990;García-Lara et al, 1996;Flärdh et al, 1997). We therefore suspect that the differences in values found by various groups are likely to result from differences in growth phase.…”

Penicillin-binding protein 2 inactivation in Escherichia coli results in cell division inhibition, which is relieved by FtsZ overexpression

“…FtsZ is distributed randomly in the cytoplasm between successive divisions but condenses to form a ring around the cell center at the onset of septation (4). The relative rate of ftsZ expression is inversely correlated with growth rate: when the growth rate decreases, ftsZ expression increases (2,17,38). The ppGpp pool size is also inversely correlated with growth rate (10) minimal medium (33) supplemented with glucose (0.4%), thiamine (10 ,ug/ml), thymine (100 ,ug/ml), and serine, glycine, and methionine (100 ,ug/ml each); relA mutants cannot grow on this medium unless isoleucine and valine (100 ,ug/ml each) are added (49,50).…”

“…2) shows that all the genes can be transcribed from two promoters located in the ddlB gene, and ftsZ has four additional promoters within the ftsA gene (2,39,40). The expression of ftsZ is inversely correlated with growth rate (2,17,38). The P01 promoter contains a so-called "gearbox" sequence, which is found in other promoters inversely regulated by growth rate (1) and, in one case, has been shown to be essential for this regulation (2).…”