Evidence for an accumulation of messenger RNA specific for extracellular protease and its relevance to the mechanism of enzyme secretion in bacteria

Both, Gerald W.; McInnes, James; Hanlon, Joan E.; May, Brian K.; Elliott, William H.

doi:10.1016/0022-2836(72)90236-7

Cited by 83 publications

(81 citation statements)

References 22 publications

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“…The observation in the present study of a highly selective inhibition of haemolysin biosynthesis might be explained by the existence of two classes of ribosomes with different sensitivities to streptomycin: one located at the periphery of the cell, perhaps associated with the cytoplasmic membrane, and the other more-orless uniformly distributed in the cytoplasm. Both et al (1972) proposed that the site of extracellular enzyme synthesis is located on the inside of the membrane. Membrane-bound ribosomes occur in bacteria and account for at least 30% of the total polyribosomes in E. coli (Varricchio, 1972).…”

Section: Discussionmentioning

confidence: 99%

Effect of four antibiotics on haemolysin production and adherence to human uroepithelial cells by Escherichia coli

Shibl¹,

Gemmell²

1983

Journal of Medical Microbiology

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Section: Discussionmentioning

confidence: 99%

Effect of four antibiotics on haemolysin production and adherence to human uroepithelial cells by Escherichia coli

Shibl¹,

Gemmell²

1983

Journal of Medical Microbiology

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“…The idea that extracellular products are synthesised or assembled on the surface of the cell membrane is attractive because many enzymes are known to be bound to the cell surface (Lampen, 1974). As a result of studies on Micrococcus sodonensis (Glew and Heath, 1971) and Bacillus amyloliquefaciens (Both et al, 1972), it was postulated that extracellular enzymes are synthesised at the cell membrane and are extruded through it.…”

Section: Discussionmentioning

confidence: 99%

Antibiotic inhibition of protease production by Pseudomonas aeruginosa

Shibl¹,

Al-Sowaygh²

1980

Journal of Medical Microbiology

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P S E U D O M O N A S AERUGZNOSAis an unusual gram-negative bacillus in that many of its pathogenic effects are believed to be caused by extracellular products (haemolysin, lecithinase, toxin and protease) and not by the so-called endotoxin moiety (Liu, Abe and Bates, 1961;Liu, 1974).Previous results (Meinke et al., 1970;Homma et al., 1975;Gray and Kreger, 1979) indicate that P. aeruginosa protease may be important in the pathogenesis of pseudomonas pneumonia. Homma et al. (1975) observed that the sera Of patients contained elevated titres of antibody to pseudomonas protease. Meinke et al. (1970) reported that intranasal administration of P. aeruginosa protease to mice produced focal and confluent haemorrhagic lung lesions, macroscopically identical to those seen in human patients (Shimizu et al., 1974). Gray and Kreger (1979) considered that protease was at least partially responsible for the lung damage in pseudomonas pneumonia.Because of the possible pathogenic importance of pseudomonas protease we investigated the in-vitro ability of antibiotics, in concentrations too low to affect greatly the growth and survival of P. aeruginosa, to suppress extracellular protease production. MATERIALS AND METHODSBacterial strain. P. aeruginosa strain SAR was isolated from a human pneumonia specimen at King Abdul Aziz University Hospital. It produced pyocyanin and was identified by the method of Buchanan and Gibbons (1974). This strain was the best producer of extracellular protease among 20 strains tested by the method described below.Culture methods and sampling. The kinetics of growth and protease production were followed for 24 h in 250-ml cultures in trypticase soy broth (TSB). The antibiotic solutions were added at the beginning of the experiment or at various times during incubation. The flasks were seeded with an overnight TSB culture grown at 37°C to give a final concentration of approximately lo5 viable organisms/ml, and were incubated at 37°C on an orbital shaker (Gallenkamp) at 140 r.p.m. Optical densities were obtained by removing aseptically 2-ml volumes of culture and reading the optical density (OD) at 490 nm in a Beckman spectrophotometer 20. Culture supernates were obtained from these samples by centrifugation at 10 000 g for 20 min. The supernates were sterilised by filtration and then used for protease assay.Assay ofprotease was by the method of Brown and Foster (1970) with agar containing 15% (v/v) sterile skimmed milk. In preliminary experiments, wells 4,9 and 12 mm in diameter were filled with serial twofold dilutions of supernate from a 24-h culture. The plates weremaintained at room temperature for 48 h. The wells 9 and 12 mm in diameter were equally satisfactory for detecting the smallest concentrations of protease. Wells 9 mm in diameter were used in all subsequent experiments. The titre was the highest dilution that produced clearing around the wells.Test for DNA. The method of Burton (1956) was used. Extraction of intracellularprotease. Ethylenediamine tetraacetate-lysozyme spheroplasts of P....

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“…The production of exoprotein under these circumstances would follow curve c (Fig. 1) and the kinetics would be the same whether or not an involvement of ' translation-extrusion sites' (Both et al, 1972) is postulated, provided they are not and do not become limiting.…”

mentioning

confidence: 87%

“…Translation-extrusion sites' are limiting with an accompanying accumulation of exoprotein mRNA. This embraces the model proposed by Both et al (1972) which can exist in two possible forms: one in which the excess of free mRNA 'queuing up' for translation is considered to be stable and the other in which it is considered to be unstable. However, in both cases, on inhibiting transcription, exoprotein would continue to be formed linearly, at its maximum rate, as long as all the 'translation-extrusion sites' remain saturated i.e.…”

mentioning

confidence: 97%

“…The kinetics of this process would be the same irrespective of whether one considers that exoprotein synthesis is initiated on free polyribosomes within the bacterial cytoplasm and that the specific secretory determinant resides in the N-terminal amino acid sequence of the exoprotein itself, as suggested by Milstein et al (1972), or, alternatively, that exoprotein mRNA associated with ribosomes is bound at special ' translation-extrusion sites ' located on the cell membrane, as proposed by Both et al (1972), provided that the availability of these sites imposes no limitation.…”

mentioning

confidence: 99%

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A Theoretical Analysis of the Kinetics of Bacterial Exoprotein Formation following Inhibition of Transcription

Coleman¹

1978

Journal of General Microbiology

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Evidence for an accumulation of messenger RNA specific for extracellular protease and its relevance to the mechanism of enzyme secretion in bacteria

Cited by 83 publications

References 22 publications

Effect of four antibiotics on haemolysin production and adherence to human uroepithelial cells by Escherichia coli

Effect of four antibiotics on haemolysin production and adherence to human uroepithelial cells by Escherichia coli

Antibiotic inhibition of protease production by Pseudomonas aeruginosa

A Theoretical Analysis of the Kinetics of Bacterial Exoprotein Formation following Inhibition of Transcription

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