Unusual Arsenate Poisoning of the F Pili of Escherichia coli

Abstract

The arsenate poisoning of R17 phage eclipse in Escherichia coli cultures grown in glycerol-containing medium has been found to be mediated by a dramatic loss in cell-associated F pili. Poisoning was very rapid and was nearly complete within 3 min at 37 C. The loss of pili was reflected by a 90% reduction in the ability of these cells to attach ribonucleic acid phage and by a reduction in the pili-per-cell ratio from 1.36 to 0.04 as determined by electron microscopy. Neither the integrity of the pilus per se nor the attachment process was affected by arsenate, for cell-free pili treated with arsenate retained the ability to attach phage. The arsenate effect on F piliation could be reversed readily without any loss in cell viability. This restoration of pili occurred under conditions of inhibited protein synthesis, implying that pools of pili protein exist in cells. In contrast to this phenomenon, cells grown in glucose-containing media were mainly resistant to arsenate poisoning as determined by phage attachment and the number of pili per cell. These results implied that arsenate poisons the ability of cells to synthesize and maintain F pili under certain specific conditions. The possible mechanism of this poisoning is discussed.

Retraction of F Pili

“…In a previous study, we reported that F pili disappeared in the presence of NaCN (11), and it has also been shown that cells poisoned with arsenate lose their pili (12). One explanation for this loss is that pili retract in the presence of energy poisons (11), and another is that pili fall off the cell when energy production is inhibited (10)(11)(12).…”

Physical and metabolic requirements for early interaction of poliovirus and human rhinovirus with HeLa cells

“…Such a model has a precedent in the effect of metabolic poisons on attachment of certain bacterial viruses. Poisoned bacterial cells lose or retract F pili and simultaneously lose ability to attach phages whose receptors reside on the pili (26,30,31). It would also be interesting to look for ultrastructural correlates for the loss of HRV2 receptors on poisoned HeLa cells.…”

Effects of high temperature on Escherichia coli F pili

“…F pili rapidly disappear from the surface of donor strains of Escherichia coli K-12 under certain conditions. These conditions include infection with filamentous, donor-specific phages (9,11); incubation in the presence of sodium cyanide (13) and arsenate (17); and temperature shifts from 37 and 250C (14). Marvin and Hohn (11) were the first to suggest that F pili could retract.…”

“…Studies of the outgrowth of F pili indicate that outgrowth requires the synthesis of ATP (16,17) and the synthesis of RNA (8). The synthesis of DNA (16) or the synthesis of protein (3,16) is not required.…”

“…Very little is known about the requirements for retraction. Retraction does not require the synthesis of ATP because pili retract in the presence of energy poisons (13,17), and it does not require the synthesis of RNA and protein because rifampin, streptolydigin, and chloramphenicol have no immediate effect on retraction in the presence of cyanide (8). Retraction is inhibited by chloramphenicol after 15 min, suggesting that retraction requires a protein whose pool size is limited (8).…”