scholarly journals Bacteriophage T4 resistance to lysis-inhibition collapse

1999 ◽  
Vol 74 (1) ◽  
pp. 1-11 ◽  
Author(s):  
STEPHEN T. ABEDON
Keyword(s):  
Latent Period ◽  
Burst Size ◽  
Bacteriophage T4 ◽  
Size Increase ◽  
Wild Type ◽  
Lysis Inhibition ◽  
T4 Bacteriophage ◽  
Infected Cells

Lysis inhibition is a mechanism of latent-period extension and burst-size increase that is induced by the T4 bacteriophage adsorption of T4-infected cells. Mutants of T4 genes imm, sp and 5 (specifically the ts1 mutant of 5) display some lysis inhibition. However, these mutants experience lysis-inhibition collapse, the lysis of lysis-inhibited cells, earlier than wild-type-infected cells (i.e. their collapse occurs prematurely). Lysis from without is a lysis induced by excessive T4 adsorption. Gp5 is an inducer of lysis from without while gpimm and gpsp effect resistance to lysis from without. This paper shows that interfering with the adsorption of phages to imm-, sp- or 5ts1-mutant-infected cells, in a variety of contexts, inhibits premature lysis-inhibition collapse. From these data it is inferred that wild-type T4-infected cells display resistance to lysis-inhibition collapse by a mechanism resembling resistance to lysis from without.

scholarly journals EXPRESSION OF A DNA REPLICATION GENE CLUSTER IN BACTERIOPHAGE T4: GENETIC LINKAGE AND THE CONTROL OF GENE PRODUCT INTERACTIONS

Genetics ◽  
1984 ◽  
Vol 107 (4) ◽  
pp. 537-549 ◽  
Author(s):  
W L Gerald ◽  
J D Karam
Keyword(s):  
Dna Replication ◽  
Genetic Linkage ◽  
Bacteriophage T4 ◽  
Inhibitory Effect ◽  
Wild Type ◽  
Essential Components ◽  
T4 Bacteriophage ◽  
Missense Mutant ◽  
Type Gene ◽  
And Control

ABSTRACT The results of this study bear on the relationship between genetic linkage and control of interactions between the protein products of different cistrons. In T4 bacteriophage, genes 45 and 44 encode essential components of the phage DNA replication multiprotein complex. T4 gene 45 maps directly upstream of gene 44 relative to the overall direction of reading of this region of the phage chromosome, but it is not known whether these two genes are cotranscribed. It has been shown that a nonsense lesion of T4 gene 45 exerts a cis-dominant inhibitory effect on growth of a missense mutant of gene 44 but not on growth of phage carrying the wild-type gene 44 allele. In previous work, we confirmed these observations on polarity of the gene 45 mutation but detected no polar effects by this lesion on synthesis of either mutant or wild-type gene 44 protein. In the present study, we demonstrate that mRNA for gene 44 protein is separable by gel electrophoresis from gene 45-protein-encoding mRNA. That is, the two proteins are not synthesized from one polycistronic message, and the cis-dominant inhibitory effect of the gene 45 mutation on gene 44 function is probably expressed at a posttranslational stage. We propose that close genetic linkage, whether or not it provides shared transcriptional and translational regulatory signals for certain clusters of functionally related cistrons, may determine the intracellular compartmentalization for synthesis of proteins encoded by these clusters. In prokaryotes, such linkage-dependent compartmentation may minimize the diffusion distances between gene products that are synthesized at low levels and are destined to interact.

scholarly journals Model for Bacteriophage T4 Development inEscherichia coli

1999 ◽  
Vol 181 (5) ◽  
pp. 1677-1683 ◽  
Author(s):  
Avinoam Rabinovitch ◽  
Hilla Hadas ◽  
Monica Einav ◽  
Zeev Melamed ◽  
Arieh Zaritsky
Keyword(s):  
Standard Deviation ◽  
Burst Size ◽  
Bacteriophage T4 ◽  
Growth Conditions ◽  
Wild Type ◽  
E Coli ◽  
Phage Development ◽  
Dependent Parameter ◽  
Mathematical Relations ◽  
Infected Bacterium

ABSTRACT Mathematical relations for the number of mature T4 bacteriophages, both inside and after lysis of an Escherichia coli cell, as a function of time after infection by a single phage were obtained, with the following five parameters: delay time until the first T4 is completed inside the bacterium (eclipse period, ν) and its standard deviation (ς), the rate at which the number of ripe T4 increases inside the bacterium during the rise period (α), and the time when the bacterium bursts (μ) and its standard deviation (β). Burst size [B = α(μ − ν)], the number of phages released from an infected bacterium, is thus a dependent parameter. A least-squares program was used to derive the values of the parameters for a variety of experimental results obtained with wild-type T4 inE. coli B/r under different growth conditions and manipulations (H. Hadas, M. Einav, I. Fishov, and A. Zaritsky, Microbiology 143:179–185, 1997). A “destruction parameter” (ζ) was added to take care of the adverse effect of chloroform on phage survival. The overall agreement between the model and the experiment is quite good. The dependence of the derived parameters on growth conditions can be used to predict phage development under other experimental manipulations.

scholarly journals Oriented Immobilization of Bacteriophages for Biosensor Applications

2009 ◽  
Vol 76 (2) ◽  
pp. 528-535 ◽  
Author(s):  
M. Tolba ◽  
O. Minikh ◽  
L. Y. Brovko ◽  
S. Evoy ◽  
M. W. Griffiths
Keyword(s):  
Magnetic Beads ◽  
Protein Gene ◽  
Specific Binding ◽  
Burst Size ◽  
Bacteriophage T4 ◽  
Host Bacterium ◽  
Capsid Protein Gene ◽  
Phage Display Technique ◽  
Oriented Immobilization ◽  
T4 Bacteriophage

ABSTRACT A method was developed for oriented immobilization of bacteriophage T4 through introduction of specific binding ligands into the phage head using a phage display technique. Fusion of the biotin carboxyl carrier protein gene (bccp) or the cellulose binding module gene (cbm) with the small outer capsid protein gene (soc) of T4 resulted in expression of the respective ligand on the phage head. Recombinant bacteriophages were characterized in terms of infectivity. It was shown that both recombinant phages retain their lytic activity and host range. However, phage head modification resulted in a decreased burst size and an increased latent period. The efficiency of bacteriophage immobilization with streptavidin-coated magnetic beads and cellulose-based materials was investigated. It was shown that recombinant bacteriophages form specific and strong bonds with their respective solid support and are able to specifically capture and infect the host bacterium. Thus, the use of immobilized BCCP-T4 bacteriophage for an Escherichia coli B assay using a phage multiplication approach and real-time PCR allowed detection of as few as 800 cells within 2 h.

scholarly journals Look Who’s Talking: T-Even Phage Lysis Inhibition, the Granddaddy of Virus-Virus Intercellular Communication Research

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 951 ◽  
Author(s):  
Stephen Abedon
Keyword(s):  
Intercellular Communication ◽  
Molecular Basis ◽  
Burst Size ◽  
Communication Process ◽  
Communication Research ◽  
Lysis Inhibition ◽  
History Of ◽  
Infected Cells ◽  
Local Densities ◽  
Original Virus

That communication can occur between virus-infected cells has been appreciated for nearly as long as has virus molecular biology. The original virus communication process specifically was that seen with T-even bacteriophages—phages T2, T4, and T6—resulting in what was labeled as a lysis inhibition. Another proposed virus communication phenomenon, also seen with T-even phages, can be described as a phage-adsorption-induced synchronized lysis-inhibition collapse. Both are mediated by virions that were released from earlier-lysing, phage-infected bacteria. Each may represent ecological responses, in terms of phage lysis timing, to high local densities of phage-infected bacteria, but for lysis inhibition also to locally reduced densities of phage-uninfected bacteria. With lysis inhibition, the outcome is a temporary avoidance of lysis, i.e., a lysis delay, resulting in increased numbers of virions (greater burst size). Synchronized lysis-inhibition collapse, by contrast, is an accelerated lysis which is imposed upon phage-infected bacteria by virions that have been lytically released from other phage-infected bacteria. Here I consider some history of lysis inhibition, its laboratory manifestation, its molecular basis, how it may benefit expressing phages, and its potential ecological role. I discuss as well other, more recently recognized examples of virus-virus intercellular communication.

The Roles of the Bacteriophage T4 r Genes in Lysis Inhibition and Fine-Structure Genetics: A New Perspective

Genetics ◽  
1998 ◽  
Vol 148 (4) ◽  
pp. 1539-1550 ◽  
Author(s):  
Patrick Paddison ◽  
Stephen T Abedon ◽  
Holly Kloos Dressman ◽  
Katherine Gailbreath ◽  
Julia Tracy ◽  
...  
Keyword(s):  
Translational Regulation ◽  
Bacteriophage T4 ◽  
Plaque Morphology ◽  
R Genes ◽  
Large Plaque ◽  
Alternate Pathway ◽  
Lysis Inhibition ◽  
Infected Cells ◽  
New Perspective

AbstractSeldom has the study of a set of genes contributed more to our understanding of molecular genetics than has the characterization of the rapid-lysis genes of bacteriophage T4. For example, T4 rII mutants were used to define gene structure and mutagen effects at the molecular level and to help unravel the genetic code. The large-plaque morphology of these mutants reflects a block in expressing lysis inhibition (LIN), the ability to delay lysis for several hours in response to sensing external related phages attacking the cell, which is a unique and highly adaptive attribute of the T4 family of phages. However, surprisingly little is known about the mechanism of LIN, or how the various r genes affect its expression. Here, we review the extensive old literature about the r genes and the lysis process and try to sort out the major players affecting lysis inhibition. We confirm that superinfection can induce lysis inhibition even while infected cells are lysing, suggesting that the signal response is virtually instantaneous and thus probably the result of post-translational regulation. We identify the rI gene as ORF tk.–2, based on sequence analysis of canonical rI mutants. The rI gene encodes a peptide of 97 amino acids (Mr = 11.1 kD; pI = 4.8) that probably is secreted into the periplasmic space. This gene is widely conserved among T-even phage. We then present a model for LIN, postulating that rI is largely responsible for regulating the gpt holin protein in response to superinfection. The evidence suggests that the rIIA and B genes are not directly involved in lysis inhibition; rather, when they are absent, an alternate pathway for lysis develops which depends on the presence of genes from any of several possible prophages and is not sensitive to lysis inhibition.

scholarly journals Experimental Examination of Bacteriophage Latent-Period Evolution as a Response to Bacterial Availability

2003 ◽  
Vol 69 (12) ◽  
pp. 7499-7506 ◽  
Author(s):  
Stephen T. Abedon ◽  
Paul Hyman ◽  
Cameron Thomas
Keyword(s):  
Population Growth ◽  
Latent Period ◽  
Generation Time ◽  
Burst Size ◽  
Lytic Bacteriophage ◽  
Wild Type ◽  
Experimental Examination ◽  
Trade Off ◽  
Culture Growth ◽  
Mutant Frequency

ABSTRACT For obligately lytic bacteriophage (phage) a trade-off exists between fecundity (burst size) and latent period (a component of generation time). This trade-off occurs because release of phage progeny from infected bacteria coincides with destruction of the machinery necessary to produce more phage progeny. Here we employ phage mutants to explore issues of phage latent-period evolution as a function of the density of phage-susceptible bacteria. Theory suggests that higher bacterial densities should select for shorter phage latent periods. Consistently, we have found that higher host densities (≥∼107 bacteria/ml) can enrich stocks of phage RB69 for variants that display shorter latent periods than the wild type. One such variant, dubbed sta5, displays a latent period that is ∼70 to 80% of that of the wild type—which is nearly as short as the RB69 eclipse period—and which has a corresponding burst size that is ∼30% of that of the wild type. We show that at higher host densities (≥∼107 bacteria/ml) the sta5 phage can outcompete the RB69 wild type, though only under conditions of direct (same-culture) competition. We interpret this advantage as corresponding to slightly faster sta5 population growth, resulting in multifold increases in mutant frequency during same-culture growth. The sta5 advantage is lost, however, given indirect (different-culture) competition between the wild type and mutant or given same-culture competition but at lower densities of phage-susceptible bacteria (≤∼106 bacteria/ml). From these observations we suggest that phage displaying very short latent periods may be viewed as specialists for propagation when bacteria within cultures are highly prevalent and transmission between cultures is easily accomplished.

scholarly journals Proteomic profiles and kinetics of development of bacteriophage T4 and its rI and rIII mutants in slowly growing Escherichia coli

2013 ◽  
Vol 94 (4) ◽  
pp. 896-905 ◽  
Author(s):  
Piotr Golec ◽  
Joanna Karczewska-Golec ◽  
Birgit Voigt ◽  
Dirk Albrecht ◽  
Thomas Schweder ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacteriophage T4 ◽  
Natural Habitat ◽  
Bacterial Growth Rate ◽  
Host Interactions ◽  
Lysis Inhibition ◽  
Phage T4 ◽  
Phage Propagation ◽  
Infected Cells ◽  
Kinetics Of

Bacteriophage T4 survival in its natural environment requires adjustment of phage development to the slow bacterial growth rate or the initiation of mechanisms of pseudolysogeny or lysis inhibition (LIN). While phage-encoded RI and probably RIII proteins seem to be crucial players in pseudolysogeny and LIN phenomena, the identity of proteins involved in the regulation of T4 development in slowly growing bacteria has remained unknown. In this work, using a chemostat system, we studied the development of wild-type T4 (T4wt) and its rI (T4rI) and rIII (T4rIII) mutants in slowly growing bacteria, where T4 did not initiate LIN or pseudolysogeny. We determined eclipse periods, phage propagation times, latent periods and burst sizes of T4wt, T4rI and T4rIII. We also compared intracellular proteomes of slowly growing Escherichia coli infected with either T4wt or the mutants. Using two-dimensional PAGE analyses we found 18 differentially expressed proteins from lysates of infected cells. Proteins whose amounts were different in cells harbouring T4wt and the mutants are involved in processes of replication, phage–host interactions or they constitute virion components. Our data indicate that functional RI and RIII proteins – apart from their already known roles in LIN and pseudolysogeny – are also necessary for the regulation of phage T4 development in slowly growing bacteria. This regulation may be more complicated than previously anticipated, with many factors influencing T4 development in its natural habitat.

scholarly journals Periplasmic Domains Define Holin-Antiholin Interactions in T4 Lysis Inhibition

2005 ◽  
Vol 187 (19) ◽  
pp. 6631-6640 ◽  
Author(s):  
Tram Anh T. Tran ◽  
Douglas K. Struck ◽  
Ry Young
Keyword(s):  
Bacteriophage T4 ◽  
Green Fluorescence Protein ◽  
Subcellular Fractionation ◽  
Plaque Morphology ◽  
Wild Type ◽  
Real Time Control ◽  
Late Gene Expression ◽  
Whole Cells ◽  
Lysis Inhibition ◽  
Periplasmic Domain

ABSTRACT Bacteriophage T4 effects host lysis with a holin, T, and an endolysin, E. T and E accumulate in the membrane and cytoplasm, respectively, throughout the period of late gene expression. At an allele-specific time, T triggers to disrupt the membrane, allowing E to enter the periplasm and attack the peptidoglycan. T triggering can be blocked by secondary infections, leading to the state of lysis inhibition (LIN). LIN requires the T4 antiholin, RI, and is sensitive to the addition of energy poisons. T is unusual among holins in having a large C-terminal periplasmic domain. The rI gene encodes a polypeptide of 97 residues, of which 72 are predicted to be a periplasmic domain. Here, we show that the periplasmic domain of RI is necessary and sufficient to block T-mediated lysis. Moreover, when overexpressed, the periplasmic domain of T (TCTD) was found to abolish LIN in T4 infections and to convert wild-type (wt) T4 plaques from small and fuzzy edged to the classic “r” large, sharp-edged plaque morphology. Although RI could be detected in whole cells, attempts to monitor it during subcellular fractionation were unsuccessful, presumably because RI is a highly unstable protein. However, fusing green fluorescence protein (GFP) to the N terminus of RI created a more stable chimera that could be demonstrated to form complexes with wild-type TCTD and also with its LIN-defective T75I variant. These results suggest that the function of the unusual periplasmic domain of T is to transduce environmental information for the real-time control of lysis timing.

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